Methods and compositions for diagnosis and prognosis of renal injury and renal failure

ABSTRACT

The present invention relates to using 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex as a prognostic biomarker in renal injuries.

The present application is a continuation of U.S. patent application Ser. No. 14/241,005, filed Mar. 4, 2014, now issued as U.S. Pat. No. 9,459,261 on Oct. 4, 2016, which is the U.S. national phase of International Application No. PCT/US2012/052298, filed Aug. 24, 2012, which designated the U.S. and claims priority to provisional U.S. patent application No. 61/528,000 filed Aug. 26, 2011, and to provisional U.S. patent application No. 61/528,003 filed Aug. 26, 2011, which are hereby incorporated in their entirety including all tables, figures, and claims.

SEQUENCE LISTING

The instant application contains a Sequence Listing which has been submitted in ASCII format via EFS-Web and is hereby incorporated by reference in its entirety. Said ASCII copy, created on Oct. 3, 2016, is named AST8104CT_SeqListing.txt and is 51 kilobytes in size.

BACKGROUND OF THE INVENTION

The following discussion of the background of the invention is merely provided to aid the reader in understanding the invention and is not admitted to describe or constitute prior art to the present invention.

The kidney is responsible for water and solute excretion from the body. Its functions include maintenance of acid-base balance, regulation of electrolyte concentrations, control of blood volume, and regulation of blood pressure. As such, loss of kidney function through injury and/or disease results in substantial morbidity and mortality. A detailed discussion of renal injuries is provided in Harrison's Principles of Internal Medicine, 17^(th) Ed., McGraw Hill, New York, pages 1741-1830, which are hereby incorporated by reference in their entirety. Renal disease and/or injury may be acute or chronic. Acute and chronic kidney disease are described as follows (from Current Medical Diagnosis & Treatment 2008, 47^(th) Ed, McGraw Hill, New York, pages 785-815, which are hereby incorporated by reference in their entirety): “Acute renal failure is worsening of renal function over hours to days, resulting in the retention of nitrogenous wastes (such as urea nitrogen) and creatinine in the blood. Retention of these substances is called azotemia. Chronic renal failure (chronic kidney disease) results from an abnormal loss of renal function over months to years”.

Acute renal failure (ARF, also known as acute kidney injury, or AKI) is an abrupt (typically detected within about 48 hours to 1 week) reduction in glomerular filtration. This loss of filtration capacity results in retention of nitrogenous (urea and creatinine) and non-nitrogenous waste products that are normally excreted by the kidney, a reduction in urine output, or both. It is reported that ARF complicates about 5% of hospital admissions, 4-15% of cardiopulmonary bypass surgeries, and up to 30% of intensive care admissions. ARF may be categorized as prerenal, intrinsic renal, or postrenal in causation. Intrinsic renal disease can be further divided into glomerular, tubular, interstitial, and vascular abnormalities. Major causes of ARF are described in the following table, which is adapted from the Merck Manual, 17^(th) ed., Chapter 222, and which is hereby incorporated by reference in their entirety:

Type Risk Factors Prerenal ECF volume depletion Excessive diuresis, hemorrhage, GI losses, loss of intravascular fluid into the extravascular space (due to ascites, peritonitis, pancreatitis, or burns), loss of skin and mucus membranes, renal salt- and water-wasting states Low cardiac output Cardiomyopathy, MI, cardiac tamponade, pulmonary embolism, pulmonary hypertension, positive-pressure mechanical ventilation Low systemic vascular Septic shock, liver failure, antihypertensive drugs resistance Increased renal vascular NSAIDs, cyclosporines, tacrolimus, hypercalcemia, resistance anaphylaxis, anesthetics, renal artery obstruction, renal vein thrombosis, sepsis, hepatorenal syndrome Decreased efferent ACE inhibitors or angiotensin II receptor blockers arteriolar tone (leading to decreased GFR from reduced glomerular transcapillary pressure, especially in patients with bilateral renal artery stenosis) Intrinsic Renal Acute tubular injury Ischemia (prolonged or severe prerenal state): surgery, hemorrhage, arterial or venous obstruction; Toxins: NSAIDs, cyclosporines, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, streptozotocin Acute glomerulonephritis ANCA-associated: Crescentic glomerulonephritis, polyarteritis nodosa, Wegener's granulomatosis; Anti- GBM glomerulonephritis: Goodpasture's syndrome; Immune-complex: Lupus glomerulonephritis, postinfectious glomerulonephritis, cryoglobulinemic glomerulonephritis Acute tubulointerstitial Drug reaction (eg, β-lactams, NSAIDs, sulfonamides, nephritis ciprofloxacin, thiazide diuretics, furosemide, phenytoin, allopurinol, pyelonephritis, papillary necrosis Acute vascular Vasculitis, malignant hypertension, thrombotic nephropathy microangiopathies, scleroderma, atheroembolism Infiltrative diseases Lymphoma, sarcoidosis, leukemia Postrenal Tubular precipitation Uric acid (tumor lysis), sulfonamides, triamterene, acyclovir, indinavir, methotrexate, ethylene glycol ingestion, myeloma protein, myoglobin Ureteral obstruction Intrinsic: Calculi, clots, sloughed renal tissue, fungus ball, edema, malignancy, congenital defects; Extrinsic: Malignancy, retroperitoneal fibrosis, ureteral trauma during surgery or high impact injury Bladder obstruction Mechanical: Benign prostatic hyperplasia, prostate cancer, bladder cancer, urethral strictures, phimosis, paraphimosis, urethral valves, obstructed indwelling urinary catheter; Neurogenic: Anticholinergic drugs, upper or lower motor neuron lesion

In the case of ischemic ARF, the course of the disease may be divided into four phases. During an initiation phase, which lasts hours to days, reduced perfusion of the kidney is evolving into injury. Glomerular ultrafiltration reduces, the flow of filtrate is reduced due to debris within the tubules, and back leakage of filtrate through injured epithelium occurs. Renal injury can be mediated during this phase by reperfusion of the kidney. Initiation is followed by an extension phase which is characterized by continued ischemic injury and inflammation and may involve endothelial damage and vascular congestion. During the maintenance phase, lasting from 1 to 2 weeks, renal cell injury occurs, and glomerular filtration and urine output reaches a minimum. A recovery phase can follow in which the renal epithelium is repaired and GFR gradually recovers. Despite this, the survival rate of subjects with ARF may be as low as about 60%.

Acute kidney injury caused by radiocontrast agents (also called contrast media) and other nephrotoxins such as cyclosporine, antibiotics including aminoglycosides and anticancer drugs such as cisplatin manifests over a period of days to about a week. Contrast induced nephropathy (CIN, which is AKI caused by radiocontrast agents) is thought to be caused by intrarenal vasoconstriction (leading to ischemic injury) and from the generation of reactive oxygen species that are directly toxic to renal tubular epithelial cells. CIN classically presents as an acute (onset within 24-48 h) but reversible (peak 3-5 days, resolution within 1 week) rise in blood urea nitrogen and serum creatinine.

A commonly reported criteria for defining and detecting AKI is an abrupt (typically within about 2-7 days or within a period of hospitalization) elevation of serum creatinine. Although the use of serum creatinine elevation to define and detect AKI is well established, the magnitude of the serum creatinine elevation and the time over which it is measured to define AKI varies considerably among publications. Traditionally, relatively large increases in serum creatinine such as 100%, 200%, an increase of at least 100% to a value over 2 mg/dL and other definitions were used to define AKI. However, the recent trend has been towards using smaller serum creatinine rises to define AKI. The relationship between serum creatinine rise, AKI and the associated health risks are reviewed in Praught and Shlipak, Curr Opin Nephrol Hypertens 14:265-270, 2005 and Chertow et al, J Am Soc Nephrol 16: 3365-3370, 2005, which, with the references listed therein, are hereby incorporated by reference in their entirety. As described in these publications, acute worsening renal function (AKI) and increased risk of death and other detrimental outcomes are now known to be associated with very small increases in serum creatinine. These increases may be determined as a relative (percent) value or a nominal value. Relative increases in serum creatinine as small as 20% from the pre-injury value have been reported to indicate acutely worsening renal function (AKI) and increased health risk, but the more commonly reported value to define AKI and increased health risk is a relative increase of at least 25%. Nominal increases as small as 0.3 mg/dL, 0.2 mg/dL or even 0.1 mg/dL have been reported to indicate worsening renal function and increased risk of death. Various time periods for the serum creatinine to rise to these threshold values have been used to define AKI, for example, ranging from 2 days, 3 days, 7 days, or a variable period defined as the time the patient is in the hospital or intensive care unit. These studies indicate there is not a particular threshold serum creatinine rise (or time period for the rise) for worsening renal function or AKI, but rather a continuous increase in risk with increasing magnitude of serum creatinine rise.

One study (Lassnigg et all, J Am Soc Nephrol 15:1597-1605, 2004, hereby incorporated by reference in its entirety) investigated both increases and decreases in serum creatinine. Patients with a mild fall in serum creatinine of −0.1 to −0.3 mg/dL following heart surgery had the lowest mortality rate. Patients with a larger fall in serum creatinine (more than or equal to −0.4 mg/dL) or any increase in serum creatinine had a larger mortality rate. These findings caused the authors to conclude that even very subtle changes in renal function (as detected by small creatinine changes within 48 hours of surgery) seriously effect patient's outcomes. In an effort to reach consensus on a unified classification system for using serum creatinine to define AKI in clinical trials and in clinical practice, Bellomo et al., Crit Care. 8(4):R204-12, 2004, which is hereby incorporated by reference in its entirety, proposes the following classifications for stratifying AKI patients:

“Risk”: serum creatinine increased 1.5 fold from baseline OR urine production of <0.5 ml/kg body weight/hr for 6 hours;

“Injury”: serum creatinine increased 2.0 fold from baseline OR urine production <0.5 ml/kg/hr for 12 h;

“Failure”: serum creatinine increased 3.0 fold from baseline OR creatinine >355 μmol/1 (with a rise of >44) or urine output below 0.3 ml/kg/hr for 24 h or anuria for at least 12 hours;

And included two clinical outcomes:

“Loss”: persistent need for renal replacement therapy for more than four weeks.

“ESRD”: end stage renal disease—the need for dialysis for more than 3 months.

These criteria are called the RIFLE criteria, which provide a useful clinical tool to classify renal status. As discussed in Kellum, Crit. Care Med. 36: S141-45, 2008 and Ricci et al., Kidney Int. 73, 538-546, 2008, each hereby incorporated by reference in its entirety, the RIFLE criteria provide a uniform definition of AKI which has been validated in numerous studies. More recently, Mehta et al., Grit. Care 11:R31 (doi:10.1186.cc5713), 2007, hereby incorporated by reference in its entirety, proposes the following similar classifications for stratifying AKI patients, which have been modified from RIFLE:

“Stage I”: increase in serum creatinine of more than or equal to 0.3 mg/dL (≧26.4 μmol/L) or increase to more than or equal to 150% (1.5-fold) from baseline OR urine output less than 0.5 mL/kg per hour for more than 6 hours;

“Stage II”: increase in serum creatinine to more than 200% (>2-fold) from baseline OR urine output less than 0.5 mL/kg per hour for more than 12 hours;

“Stage III”: increase in serum creatinine to more than 300% (>3-fold) from baseline OR serum creatinine ≧354 μmol/L accompanied by an acute increase of at least 44 μmol/L OR urine output less than 0.3 mL/kg per hour for 24 hours or anuria for 12 hours.

The CIN Consensus Working Panel (McCollough et al, Rev Cardiovasc Med. 2006; 7(4):177-197, hereby incorporated by reference in its entirety) uses a serum creatinine rise of 25% to define Contrast induced nephropathy (which is a type of AKI). Although various groups propose slightly different criteria for using serum creatinine to detect AKI, the consensus is that small changes in serum creatinine, such as 0.3 mg/dL or 25%, are sufficient to detect AKI (worsening renal function) and that the magnitude of the serum creatinine change is an indicator of the severity of the AKI and mortality risk.

Although serial measurement of serum creatinine over a period of days is an accepted method of detecting and diagnosing AKI and is considered one of the most important tools to evaluate AKI patients, serum creatinine is generally regarded to have several limitations in the diagnosis, assessment and monitoring of AKI patients. The time period for serum creatinine to rise to values (e.g., a 0.3 mg/dL or 25% rise) considered diagnostic for AKI can be 48 hours or longer depending on the definition used. Since cellular injury in AKI can occur over a period of hours, serum creatinine elevations detected at 48 hours or longer can be a late indicator of injury, and relying on serum creatinine can thus delay diagnosis of AKI. Furthermore, serum creatinine is not a good indicator of the exact kidney status and treatment needs during the most acute phases of AKI when kidney function is changing rapidly. Some patients with AKI will recover fully, some will need dialysis (either short term or long term) and some will have other detrimental outcomes including death, major adverse cardiac events and chronic kidney disease. Because serum creatinine is a marker of filtration rate, it does not differentiate between the causes of AKI (pre-renal, intrinsic renal, post-renal obstruction, atheroembolic, etc) or the category or location of injury in intrinsic renal disease (for example, tubular, glomerular or interstitial in origin). Urine output is similarly limited, Knowing these things can be of vital importance in managing and treating patients with AKI.

These limitations underscore the need for better methods to detect and assess AKI, particularly in the early and subclinical stages, but also in later stages when recovery and repair of the kidney can occur. Furthermore, there is a need to better identify patients who are at risk of having an AKI.

BRIEF SUMMARY OF THE INVENTION

It is an object of the invention to provide methods and compositions for evaluating renal function in a subject. As described herein, measurement of one or more biomarkers selected from the group consisting of Heat shock 70 kDa protein 1, Alpha-1-antitrypsin Neutrophil elastase complex, Stromelysin-1:Metalloproteinase inhibitor 2 complex, 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex, Insulin-like growth factor 1 receptor, Myeloid differentiation primary response protein MyD88, Neuronal cell adhesion molecule, and Tumor necrosis factor ligand superfamily member 10 (each referred to herein as a “kidney injury marker”) can be used for diagnosis, prognosis, risk stratification, staging, monitoring, categorizing and determination of further diagnosis and treatment regimens in subjects suffering or at risk of suffering from an injury to renal function, reduced renal function, and/or acute renal failure (also called acute kidney injury).

The kidney injury markers of the present invention may be used, individually or in panels comprising a plurality of kidney injury markers, for risk stratification (that is, to identify subjects at risk for a future injury to renal function, for future progression to reduced renal function, for future progression to ARF, for future improvement in renal function, etc.); for diagnosis of existing disease (that is, to identify subjects who have suffered an injury to renal function, who have progressed to reduced renal function, who have progressed to ARF, etc.); for monitoring for deterioration or improvement of renal function; and for predicting a future medical outcome, such as improved or worsening renal function, a decreased or increased mortality risk, a decreased or increased risk that a subject will require renal replacement therapy (i.e., hemodialysis, peritoneal dialysis, hemofiltration, and/or renal transplantation, a decreased or increased risk that a subject will recover from an injury to renal function, a decreased or increased risk that a subject will recover from ARF, a decreased or increased risk that a subject will progress to end stage renal disease, a decreased or increased risk that a subject will progress to chronic renal failure, a decreased or increased risk that a subject will suffer rejection of a transplanted kidney, etc.

In a first aspect, the present invention relates to methods for evaluating renal status in a subject. These methods comprise performing an assay method that is configured to detect one or more biomarkers selected from the group consisting of Heat shock 70 kDa protein 1, Alpha-1-antitrypsin Neutrophil elastase complex, Stromelysin-1:Metalloproteinase inhibitor 2 complex, 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex, Insulin-like growth factor 1 receptor, Myeloid differentiation primary response protein MyD88, Neuronal cell adhesion molecule, and Tumor necrosis factor ligand superfamily member 10 is/are then correlated to the renal status of the subject. This correlation to renal status may include correlating the assay result(s) to one or more of risk stratification, diagnosis, prognosis, staging, classifying and monitoring of the subject as described herein. Thus, the present invention utilizes one or more kidney injury markers of the present invention for the evaluation of renal injury.

In certain embodiments, the methods for evaluating renal status described herein are methods for risk stratification of the subject; that is, assigning a likelihood of one or more future changes in renal status to the subject. In these embodiments, the assay result(s) is/are correlated to one or more such future changes. The following are preferred risk stratification embodiments.

In preferred risk stratification embodiments, these methods comprise determining a subject's risk for a future injury to renal function, and the assay result(s) is/are correlated to a likelihood of such a future injury to renal function. For example, the measured concentration(s) may each be compared to a threshold value. For a “positive going” kidney injury marker, an increased likelihood of suffering a future injury to renal function is assigned to the subject when the measured concentration is above the threshold, relative to a likelihood assigned when the measured concentration is below the threshold. For a “negative going” kidney injury marker, an increased likelihood of suffering a future injury to renal function is assigned to the subject when the measured concentration is below the threshold, relative to a likelihood assigned when the measured concentration is above the threshold.

In other preferred risk stratification embodiments, these methods comprise determining a subject's risk for future reduced renal function, and the assay result(s) is/are correlated to a likelihood of such reduced renal function. For example, the measured concentrations may each be compared to a threshold value. For a “positive going” kidney injury marker, an increased likelihood of suffering a future reduced renal function is assigned to the subject when the measured concentration is above the threshold, relative to a likelihood assigned when the measured concentration is below the threshold. For a “negative going” kidney injury marker, an increased likelihood of future reduced renal function is assigned to the subject when the measured concentration is below the threshold, relative to a likelihood assigned when the measured concentration is above the threshold.

In still other preferred risk stratification embodiments, these methods comprise determining a subject's likelihood for a future improvement in renal function, and the assay result(s) is/are correlated to a likelihood of such a future improvement in renal function. For example, the measured concentration(s) may each be compared to a threshold value. For a “positive going” kidney injury marker, an increased likelihood of a future improvement in renal function is assigned to the subject when the measured concentration is below the threshold, relative to a likelihood assigned when the measured concentration is above the threshold. For a “negative going” kidney injury marker, an increased likelihood of a future improvement in renal function is assigned to the subject when the measured concentration is above the threshold, relative to a likelihood assigned when the measured concentration is below the threshold.

In yet other preferred risk stratification embodiments, these methods comprise determining a subject's risk for progression to ARF, and the result(s) is/are correlated to a likelihood of such progression to ARF. For example, the measured concentration(s) may each be compared to a threshold value. For a “positive going” kidney injury marker, an increased likelihood of progression to ARF is assigned to the subject when the measured concentration is above the threshold, relative to a likelihood assigned when the measured concentration is below the threshold. For a “negative going” kidney injury marker, an increased likelihood of progression to ARF is assigned to the subject when the measured concentration is below the threshold, relative to a likelihood assigned when the measured concentration is above the threshold.

And in other preferred risk stratification embodiments, these methods comprise determining a subject's outcome risk, and the assay result(s) is/are correlated to a likelihood of the occurrence of a clinical outcome related to a renal injury suffered by the subject. For example, the measured concentration(s) may each be compared to a threshold value. For a “positive going” kidney injury marker, an increased likelihood of one or more of: acute kidney injury, progression to a worsening stage of AKI, mortality, a requirement for renal replacement therapy, a requirement for withdrawal of renal toxins, end stage renal disease, heart failure, stroke, myocardial infarction, progression to chronic kidney disease, etc., is assigned to the subject when the measured concentration is above the threshold, relative to a likelihood assigned when the measured concentration is below the threshold. For a “negative going” kidney injury marker, an increased likelihood of one or more of: acute kidney injury, progression to a worsening stage of AKI, mortality, a requirement for renal replacement therapy, a requirement for withdrawal of renal toxins, end stage renal disease, heart failure, stroke, myocardial infarction, progression to chronic kidney disease, etc., is assigned to the subject when the measured concentration is below the threshold, relative to a likelihood assigned when the measured concentration is above the threshold.

In such risk stratification embodiments, preferably the likelihood or risk assigned is that an event of interest is more or less likely to occur within 180 days of the time at which the body fluid sample is obtained from the subject. In particularly preferred embodiments, the likelihood or risk assigned relates to an event of interest occurring within a shorter time period such as 18 months, 120 days, 90 days, 60 days, 45 days, 30 days, 21 days, 14 days, 7 days, 5 days, 96 hours, 72 hours, 48 hours, 36 hours, 24 hours, 12 hours, or less. A risk at 0 hours of the time at which the body fluid sample is obtained from the subject is equivalent to diagnosis of a current condition.

In preferred risk stratification embodiments, the subject is selected for risk stratification based on the pre-existence in the subject of one or more known risk factors for prerenal, intrinsic renal, or postrenal ARF. For example, a subject undergoing or having undergone major vascular surgery, coronary artery bypass, or other cardiac surgery; a subject having pre-existing congestive heart failure, preeclampsia, eclampsia, diabetes mellitus, hypertension, coronary artery disease, proteinuria, renal insufficiency, glomerular filtration below the normal range, cirrhosis, serum creatinine above the normal range, or sepsis; or a subject exposed to NSAIDs, cyclosporines, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, or streptozotocin are all preferred subjects for monitoring risks according to the methods described herein. This list is not meant to be limiting. By “pre-existence” in this context is meant that the risk factor exists at the time the body fluid sample is obtained from the subject. In particularly preferred embodiments, a subject is chosen for risk stratification based on an existing diagnosis of injury to renal function, reduced renal function, or ARF.

In other embodiments, the methods for evaluating renal status described herein are methods for diagnosing a renal injury in the subject; that is, assessing whether or not a subject has suffered from an injury to renal function, reduced renal function, or ARF. In these embodiments, the assay result(s), for example measured concentration(s) of one or more biomarkers selected from the group consisting of Heat shock 70 kDa protein 1, Alpha-1-antitrypsin Neutrophil elastase complex, Stromelysin-1:Metalloproteinase inhibitor 2 complex, 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex, Insulin-like growth factor 1 receptor, Myeloid differentiation primary response protein MyD88, Neuronal cell adhesion molecule, and Tumor necrosis factor ligand superfamily member 10 is/are correlated to the occurrence or nonoccurrence of a change in renal status. The following are preferred diagnostic embodiments.

In preferred diagnostic embodiments, these methods comprise diagnosing the occurrence or nonoccurrence of an injury to renal function, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of such an injury. For example, each of the measured concentration(s) may be compared to a threshold value. For a positive going marker, an increased likelihood of the occurrence of an injury to renal function is assigned to the subject when the measured concentration is above the threshold (relative to the likelihood assigned when the measured concentration is below the threshold); alternatively, when the measured concentration is below the threshold, an increased likelihood of the nonoccurrence of an injury to renal function may be assigned to the subject (relative to the likelihood assigned when the measured concentration is above the threshold). For a negative going marker, an increased likelihood of the occurrence of an injury to renal function is assigned to the subject when the measured concentration is below the threshold (relative to the likelihood assigned when the measured concentration is above the threshold); alternatively, when the measured concentration is above the threshold, an increased likelihood of the nonoccurrence of an injury to renal function may be assigned to the subject (relative to the likelihood assigned when the measured concentration is below the threshold).

In other preferred diagnostic embodiments, these methods comprise diagnosing the occurrence or nonoccurrence of reduced renal function, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of an injury causing reduced renal function. For example, each of the measured concentration(s) may be compared to a threshold value. For a positive going marker, an increased likelihood of the occurrence of an injury causing reduced renal function is assigned to the subject when the measured concentration is above the threshold (relative to the likelihood assigned when the measured concentration is below the threshold); alternatively, when the measured concentration is below the threshold, an increased likelihood of the nonoccurrence of an injury causing reduced renal function may be assigned to the subject (relative to the likelihood assigned when the measured concentration is above the threshold). For a negative going marker, an increased likelihood of the occurrence of an injury causing reduced renal function is assigned to the subject when the measured concentration is below the threshold (relative to the likelihood assigned when the measured concentration is above the threshold); alternatively, when the measured concentration is above the threshold, an increased likelihood of the nonoccurrence of an injury causing reduced renal function may be assigned to the subject (relative to the likelihood assigned when the measured concentration is below the threshold).

In yet other preferred diagnostic embodiments, these methods comprise diagnosing the occurrence or nonoccurrence of ARF, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of an injury causing ARF. For example, each of the measured concentration(s) may be compared to a threshold value. For a positive going marker, an increased likelihood of the occurrence of ARF is assigned to the subject when the measured concentration is above the threshold (relative to the likelihood assigned when the measured concentration is below the threshold); alternatively, when the measured concentration is below the threshold, an increased likelihood of the nonoccurrence of ARF may be assigned to the subject (relative to the likelihood assigned when the measured concentration is above the threshold). For a negative going marker, an increased likelihood of the occurrence of ARF is assigned to the subject when the measured concentration is below the threshold (relative to the likelihood assigned when the measured concentration is above the threshold); alternatively, when the measured concentration is above the threshold, an increased likelihood of the nonoccurrence of ARF may be assigned to the subject (relative to the likelihood assigned when the measured concentration is below the threshold).

In still other preferred diagnostic embodiments, these methods comprise diagnosing a subject as being in need of renal replacement therapy, and the assay result(s) is/are correlated to a need for renal replacement therapy. For example, each of the measured concentration(s) may be compared to a threshold value. For a positive going marker, an increased likelihood of the occurrence of an injury creating a need for renal replacement therapy is assigned to the subject when the measured concentration is above the threshold (relative to the likelihood assigned when the measured concentration is below the threshold); alternatively, when the measured concentration is below the threshold, an increased likelihood of the nonoccurrence of an injury creating a need for renal replacement therapy may be assigned to the subject (relative to the likelihood assigned when the measured concentration is above the threshold). For a negative going marker, an increased likelihood of the occurrence of an injury creating a need for renal replacement therapy is assigned to the subject when the measured concentration is below the threshold (relative to the likelihood assigned when the measured concentration is above the threshold); alternatively, when the measured concentration is above the threshold, an increased likelihood of the nonoccurrence of an injury creating a need for renal replacement therapy may be assigned to the subject (relative to the likelihood assigned when the measured concentration is below the threshold).

In still other preferred diagnostic embodiments, these methods comprise diagnosing a subject as being in need of renal transplantation, and the assay result (s0 is/are correlated to a need for renal transplantation. For example, each of the measured concentration(s) may be compared to a threshold value. For a positive going marker, an increased likelihood of the occurrence of an injury creating a need for renal transplantation is assigned to the subject when the measured concentration is above the threshold (relative to the likelihood assigned when the measured concentration is below the threshold); alternatively, when the measured concentration is below the threshold, an increased likelihood of the nonoccurrence of an injury creating a need for renal transplantation may be assigned to the subject (relative to the likelihood assigned when the measured concentration is above the threshold). For a negative going marker, an increased likelihood of the occurrence of an injury creating a need for renal transplantation is assigned to the subject when the measured concentration is below the threshold (relative to the likelihood assigned when the measured concentration is above the threshold); alternatively, when the measured concentration is above the threshold, an increased likelihood of the nonoccurrence of an injury creating a need for renal transplantation may be assigned to the subject (relative to the likelihood assigned when the measured concentration is below the threshold).

In still other embodiments, the methods for evaluating renal status described herein are methods for monitoring a renal injury in the subject; that is, assessing whether or not renal function is improving or worsening in a subject who has suffered from an injury to renal function, reduced renal function, or ARF. In these embodiments, the assay result(s), for example measured concentration(s) of one or more biomarkers selected from the group consisting of Heat shock 70 kDa protein 1, Alpha-1-antitrypsin Neutrophil elastase complex, Stromelysin-1:Metalloproteinase inhibitor 2 complex, 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex, Insulin-like growth factor 1 receptor, Myeloid differentiation primary response protein MyD88, Neuronal cell adhesion molecule, and Tumor necrosis factor ligand superfamily member 10 receptor is/are correlated to the occurrence or nonoccurrence of a change in renal status. The following are preferred monitoring embodiments.

In preferred monitoring embodiments, these methods comprise monitoring renal status in a subject suffering from an injury to renal function, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of a change in renal status in the subject. For example, the measured concentration(s) may be compared to a threshold value. For a positive going marker, when the measured concentration is above the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is below the threshold, an improvement of renal function may be assigned to the subject. For a negative going marker, when the measured concentration is below the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is above the threshold, an improvement of renal function may be assigned to the subject.

In other preferred monitoring embodiments, these methods comprise monitoring renal status in a subject suffering from reduced renal function, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of a change in renal status in the subject. For example, the measured concentration(s) may be compared to a threshold value. For a positive going marker, when the measured concentration is above the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is below the threshold, an improvement of renal function may be assigned to the subject. For a negative going marker, when the measured concentration is below the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is above the threshold, an improvement of renal function may be assigned to the subject.

In yet other preferred monitoring embodiments, these methods comprise monitoring renal status in a subject suffering from acute renal failure, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of a change in renal status in the subject. For example, the measured concentration(s) may be compared to a threshold value. For a positive going marker, when the measured concentration is above the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is below the threshold, an improvement of renal function may be assigned to the subject. For a negative going marker, when the measured concentration is below the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is above the threshold, an improvement of renal function may be assigned to the subject.

In other additional preferred monitoring embodiments, these methods comprise monitoring renal status in a subject at risk of an injury to renal function due to the pre-existence of one or more known risk factors for prerenal, intrinsic renal, or postrenal ARF, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of a change in renal status in the subject. For example, the measured concentration(s) may be compared to a threshold value. For a positive going marker, when the measured concentration is above the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is below the threshold, an improvement of renal function may be assigned to the subject. For a negative going marker, when the measured concentration is below the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is above the threshold, an improvement of renal function may be assigned to the subject.

In still other embodiments, the methods for evaluating renal status described herein are methods for classifying a renal injury in the subject; that is, determining whether a renal injury in a subject is prerenal, intrinsic renal, or postrenal; and/or further subdividing these classes into subclasses such as acute tubular injury, acute glomerulonephritis acute tubulointerstitial nephritis, acute vascular nephropathy, or infiltrative disease; and/or assigning a likelihood that a subject will progress to a particular RIFLE stage. In these embodiments, the assay result(s), for example measured concentration(s) of one or more biomarkers selected from the group consisting of Heat shock 70 kDa protein 1, Alpha-1-antitrypsin Neutrophil elastase complex, Stromelysin-1:Metalloproteinase inhibitor 2 complex, 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex, Insulin-like growth factor 1 receptor, Myeloid differentiation primary response protein MyD88, Neuronal cell adhesion molecule, and Tumor necrosis factor ligand superfamily member 10 is/are correlated to a particular class and/or subclass. The following are preferred classification embodiments.

In preferred classification embodiments, these methods comprise determining whether a renal injury in a subject is prerenal, intrinsic renal, or postrenal; and/or further subdividing these classes into subclasses such as acute tubular injury, acute glomerulonephritis acute tubulointerstitial nephritis, acute vascular nephropathy, or infiltrative disease; and/or assigning a likelihood that a subject will progress to a particular RIFLE stage, and the assay result(s) is/are correlated to the injury classification for the subject. For example, the measured concentration may be compared to a threshold value, and when the measured concentration is above the threshold, a particular classification is assigned; alternatively, when the measured concentration is below the threshold, a different classification may be assigned to the subject.

A variety of methods may be used by the skilled artisan to arrive at a desired threshold value for use in these methods. For example, the threshold value may be determined from a population of normal subjects by selecting a concentration representing the 75th, 85th, 90th, 95th, or 99th percentile of a kidney injury marker measured in such normal subjects. Alternatively, the threshold value may be determined from a “diseased” population of subjects, e.g., those suffering from an injury or having a predisposition for an injury (e.g., progression to ARF or some other clinical outcome such as death, dialysis, renal transplantation, etc.), by selecting a concentration representing the 75th, 85th, 90th, 95th, or 99th percentile of a kidney injury marker measured in such subjects. In another alternative, the threshold value may be determined from a prior measurement of a kidney injury marker in the same subject; that is, a temporal change in the level of a kidney injury marker in the subject may be used to assign risk to the subject.

The foregoing discussion is not meant to imply, however, that the kidney injury markers of the present invention must be compared to corresponding individual thresholds. Methods for combining assay results can comprise the use of multivariate logistical regression, loglinear modeling, neural network analysis, n-of-m analysis, decision tree analysis, calculating ratios of markers, etc. This list is not meant to be limiting. In these methods, a composite result which is determined by combining individual markers may be treated as if it is itself a marker; that is, a threshold may be determined for the composite result as described herein for individual markers, and the composite result for an individual patient compared to this threshold.

The ability of a particular test to distinguish two populations can be established using ROC analysis. For example, ROC curves established from a “first” subpopulation which is predisposed to one or more future changes in renal status, and a “second” subpopulation which is not so predisposed can be used to calculate a ROC curve, and the area under the curve provides a measure of the quality of the test. Preferably, the tests described herein provide a ROC curve area greater than 0.5, preferably at least 0.6, more preferably 0.7, still more preferably at least 0.8, even more preferably at least 0.9, and most preferably at least 0.95.

In certain aspects, the measured concentration of one or more kidney injury markers, or a composite of such markers, may be treated as continuous variables. For example, any particular concentration can be converted into a corresponding probability of a future reduction in renal function for the subject, the occurrence of an injury, a classification, etc. In yet another alternative, a threshold that can provide an acceptable level of specificity and sensitivity in separating a population of subjects into “bins” such as a “first” subpopulation (e.g., which is predisposed to one or more future changes in renal status, the occurrence of an injury, a classification, etc.) and a “second” subpopulation which is not so predisposed. A threshold value is selected to separate this first and second population by one or more of the following measures of test accuracy:

an odds ratio greater than 1, preferably at least about 2 or more or about 0.5 or less, more preferably at least about 3 or more or about 0.33 or less, still more preferably at least about 4 or more or about 0.25 or less, even more preferably at least about 5 or more or about 0.2 or less, and most preferably at least about 10 or more or about 0.1 or less; a specificity of greater than 0.5, preferably at least about 0.6, more preferably at least about 0.7, still more preferably at least about 0.8, even more preferably at least about 0.9 and most preferably at least about 0.95, with a corresponding sensitivity greater than 0.2, preferably greater than about 0.3, more preferably greater than about 0.4, still more preferably at least about 0.5, even more preferably about 0.6, yet more preferably greater than about 0.7, still more preferably greater than about 0.8, more preferably greater than about 0.9, and most preferably greater than about 0.95; a sensitivity of greater than 0.5, preferably at least about 0.6, more preferably at least about 0.7, still more preferably at least about 0.8, even more preferably at least about 0.9 and most preferably at least about 0.95, with a corresponding specificity greater than 0.2, preferably greater than about 0.3, more preferably greater than about 0.4, still more preferably at least about 0.5, even more preferably about 0.6, yet more preferably greater than about 0.7, still more preferably greater than about 0.8, more preferably greater than about 0.9, and most preferably greater than about 0.95; at least about 75% sensitivity, combined with at least about 75% specificity; a positive likelihood ratio (calculated as sensitivity/(1-specificity)) of greater than 1, at least about 2, more preferably at least about 3, still more preferably at least about 5, and most preferably at least about 10; or a negative likelihood ratio (calculated as (1-sensitivity)/specificity) of less than 1, less than or equal to about 0.5, more preferably less than or equal to about 0.3, and most preferably less than or equal to about 0.1. The term “about” in the context of any of the above measurements refers to +/−5% of a given measurement.

Multiple thresholds may also be used to assess renal status in a subject. For example, a “first” subpopulation which is predisposed to one or more future changes in renal status, the occurrence of an injury, a classification, etc., and a “second” subpopulation which is not so predisposed can be combined into a single group. This group is then subdivided into three or more equal parts (known as tertiles, quartiles, quintiles, etc., depending on the number of subdivisions). An odds ratio is assigned to subjects based on which subdivision they fall into. If one considers a tertile, the lowest or highest tertile can be used as a reference for comparison of the other subdivisions. This reference subdivision is assigned an odds ratio of 1. The second tertile is assigned an odds ratio that is relative to that first tertile. That is, someone in the second tertile might be 3 times more likely to suffer one or more future changes in renal status in comparison to someone in the first tertile. The third tertile is also assigned an odds ratio that is relative to that first tertile.

In certain embodiments, the assay method is an immunoassay. Antibodies for use in such assays will specifically bind a full length kidney injury marker of interest, and may also bind one or more polypeptides that are “related” thereto, as that term is defined hereinafter. Numerous immunoassay formats are known to those of skill in the art. Preferred body fluid samples are selected from the group consisting of urine, blood, serum, saliva, tears, and plasma. In the case of those kidney injury markers which are membrane proteins as described hereinafter, preferred assays detect soluble forms thereof.

The foregoing method steps should not be interpreted to mean that the kidney injury marker assay result(s) is/are used in isolation in the methods described herein. Rather, additional variables or other clinical indicia may be included in the methods described herein. For example, a risk stratification, diagnostic, classification, monitoring, etc. method may combine the assay result(s) with one or more variables measured for the subject selected from the group consisting of demographic information (e.g., weight, sex, age, race), medical history (e.g., family history, type of surgery, pre-existing disease such as aneurism, congestive heart failure, preeclampsia, eclampsia, diabetes mellitus, hypertension, coronary artery disease, proteinuria, renal insufficiency, or sepsis, type of toxin exposure such as NSAIDs, cyclosporines, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, or streptozotocin), clinical variables (e.g., blood pressure, temperature, respiration rate), risk scores (APACHE score, PREDICT score, TIMI Risk Score for UA/NSTEMI, Framingham Risk Score, risk scores of Thakar et al. (J. Am. Soc. Nephrol. 16: 162-68, 2005), Mehran et al. (J. Am. Coll. Cardiol. 44: 1393-99, 2004), Wijeysundera et al. (JAMA 297: 1801-9, 2007), Goldstein and Chawla (Clin. J. Am. Soc. Nephrol. 5: 943-49, 2010), or Chawla et al. (Kidney Intl. 68: 2274-80, 2005)), a glomerular filtration rate, an estimated glomerular filtration rate, a urine production rate, a serum or plasma creatinine concentration, a urine creatinine concentration, a fractional excretion of sodium, a urine sodium concentration, a urine creatinine to serum or plasma creatinine ratio, a urine specific gravity, a urine osmolality, a urine urea nitrogen to plasma urea nitrogen ratio, a plasma BUN to creatnine ratio, a renal failure index calculated as urine sodium/(urine creatinine/plasma creatinine), a serum or plasma neutrophil gelatinase (NGAL) concentration, a urine NGAL concentration, a serum or plasma cystatin C concentration, a serum or plasma cardiac troponin concentration, a serum or plasma BNP concentration, a serum or plasma NTproBNP concentration, and a serum or plasma proBNP concentration. Other measures of renal function which may be combined with one or more kidney injury marker assay result(s) are described hereinafter and in Harrison's Principles of Internal Medicine, 17^(th) Ed., McGraw Hill, New York, pages 1741-1830, and Current Medical Diagnosis & Treatment 2008, 47^(th) Ed, McGraw Hill, New York, pages 785-815, each of which are hereby incorporated by reference in their entirety.

When more than one marker is measured, the individual markers may be measured in samples obtained at the same time, or may be determined from samples obtained at different (e.g., an earlier or later) times. The individual markers may also be measured on the same or different body fluid samples. For example, one kidney injury marker may be measured in a serum or plasma sample and another kidney injury marker may be measured in a urine sample. In addition, assignment of a likelihood may combine an individual kidney injury marker assay result with temporal changes in one or more additional variables.

In various related aspects, the present invention also relates to devices and kits for performing the methods described herein. Suitable kits comprise reagents sufficient for performing an assay for at least one of the described kidney injury markers, together with instructions for performing the described threshold comparisons.

In certain embodiments, reagents for performing such assays are provided in an assay device, and such assay devices may be included in such a kit. Preferred reagents can comprise one or more solid phase antibodies, the solid phase antibody comprising antibody that detects the intended biomarker target(s) bound to a solid support. In the case of sandwich immunoassays, such reagents can also include one or more detectably labeled antibodies, the detectably labeled antibody comprising antibody that detects the intended biomarker target(s) bound to a detectable label. Additional optional elements that may be provided as part of an assay device are described hereinafter.

Detectable labels may include molecules that are themselves detectable (e.g., fluorescent moieties, electrochemical labels, ecl (electrochemical luminescence) labels, metal chelates, colloidal metal particles, etc.) as well as molecules that may be indirectly detected by production of a detectable reaction product (e.g., enzymes such as horseradish peroxidase, alkaline phosphatase, etc.) or through the use of a specific binding molecule which itself may be detectable (e.g., a labeled antibody that binds to the second antibody, biotin, digoxigenin, maltose, oligohistidine, 2,4-dintrobenzene, phenylarsenate, ssDNA, dsDNA, etc.).

Generation of a signal from the signal development element can be performed using various optical, acoustical, and electrochemical methods well known in the art. Examples of detection modes include fluorescence, radiochemical detection, reflectance, absorbance, amperometry, conductance, impedance, interferometry, ellipsometry, etc. In certain of these methods, the solid phase antibody is coupled to a transducer (e.g., a diffraction grating, electrochemical sensor, etc) for generation of a signal, while in others, a signal is generated by a transducer that is spatially separate from the solid phase antibody (e.g., a fluorometer that employs an excitation light source and an optical detector). This list is not meant to be limiting. Antibody-based biosensors may also be employed to determine the presence or amount of analytes that optionally eliminate the need for a labeled molecule.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to methods and compositions for diagnosis, differential diagnosis, risk stratification, monitoring, classifying and determination of treatment regimens in subjects suffering or at risk of suffering from injury to renal function, reduced renal function and/or acute renal failure through measurement of one or more kidney injury markers. In various embodiments, a measured concentration of one or more biomarkers selected from the group consisting of Heat shock 70 kDa protein 1, Alpha-1-antitrypsin Neutrophil elastase complex, Stromelysin-1:Metalloproteinase inhibitor 2 complex, 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex, Insulin-like growth factor 1 receptor, Myeloid differentiation primary response protein MyD88, Neuronal cell adhesion molecule, and Tumor necrosis factor ligand superfamily member 10 or one or more markers related thereto, are correlated to the renal status of the subject.

For purposes of this document, the following definitions apply:

As used herein, an “injury to renal function” is an abrupt (within 14 days, preferably within 7 days, more preferably within 72 hours, and still more preferably within 48 hours) measurable reduction in a measure of renal function. Such an injury may be identified, for example, by a decrease in glomerular filtration rate or estimated GFR, a reduction in urine output, an increase in serum creatinine, an increase in serum cystatin C, a requirement for renal replacement therapy, etc. “Improvement in Renal Function” is an abrupt (within 14 days, preferably within 7 days, more preferably within 72 hours, and still more preferably within 48 hours) measurable increase in a measure of renal function. Preferred methods for measuring and/or estimating GFR are described hereinafter.

As used herein, “reduced renal function” is an abrupt (within 14 days, preferably within 7 days, more preferably within 72 hours, and still more preferably within 48 hours) reduction in kidney function identified by an absolute increase in serum creatinine of greater than or equal to 0.1 mg/dL (≧8.8 μmol/L), a percentage increase in serum creatinine of greater than or equal to 20% (1.2-fold from baseline), or a reduction in urine output (documented oliguria of less than 0.5 ml/kg per hour).

As used herein, “acute renal failure” or “ARF” is an abrupt (within 14 days, preferably within 7 days, more preferably within 72 hours, and still more preferably within 48 hours) reduction in kidney function identified by an absolute increase in serum creatinine of greater than or equal to 0.3 mg/dl (≧26.4 μmol/1), a percentage increase in serum creatinine of greater than or equal to 50% (1.5-fold from baseline), or a reduction in urine output (documented oliguria of less than 0.5 ml/kg per hour for at least 6 hours). This term is synonymous with “acute kidney injury” or “AKI.”

As used herein, the term “Heat shock 70 kDa protein 1” refers to one or more polypeptides present in a biological sample that are derived from the Heat shock 70 kDa protein 1 precursor (human precursor Swiss-Prot P08107 (SEQ ID NO: 1)).

        10         20         30         40 MAKAAAIGID LGTTYSCVGV FQHGKVEIIA NDQGNRTTPS         50         60         70         80 YVAFTDTERL IGDAAKNQVA LNPQNTVFDA KRLIGRKFGD         90        100        110        120 PVVQSDMKHW PFQVINDGDK PKVQVSYKGE TKAFYPEEIS        130        140        150        160 SMVLTKMKEI AEAYLGYPVT NAVITVPAYF NDSQRQATKD        170        180        190        200 AGVIAGLNVL RIINEPTAAA IAYGLDRTGK GERNVLIFDL        210        220        230        240 GGGTFDVSIL TIDDGIFEVK ATAGDTHLGG EDFDNRLVNH        250        260        270        280 FVEEFKRKHK KDISQNKRAV RRLRTACERA KRTLSSSTQA        290        300        310        320 SLEIDSLFEG IDFYTSITRA RFEELCSDLF RSTLEPVEKA        330        340        350        360 LRDAKLDKAQ IHDLVLVGGS TRIPKVQKLL QDFFNGRDLN        370        380        390        400 KSINPDEAVA YGAAVQAAIL MGDKSENVQD LLLLDVAPLS        410        420        430        440 LGLETAGGVM TALIKRNSTI PTKQTQIFTT YSDNQPGVLI        450        460        470        480 QVYEGERAMT KDNNLLGRFE LSGIPPAPRG VPQIEVTFDI        490        500        510        520 DANGILNVTA TDKSTGKANK ITITNDKGRL SKEEIERMVQ        530        540        550        560 EAEKYKAEDE VQRERVSAKN ALESYAFNMK SAVEDEGLKG        570        580        590        600 KISEADKKKV LDKCQEVISW LDANTLAEKD EFEHKRKELE        610        620        630        640 QVCNPIISGL YQGAGGPGPG GFGAQGPKGG SGSGPTIEEV D

The following domains have been identified in Heat shock 70 kDa protein 1:

Residues Length Domain ID 1 1 Initiator methionine 2-641 640 Heat shock 70 kDa protein 1

As used herein, the term “Stromelysin-1:Metalloproteinase inhibitor 2 complex” refers to a polypeptide complex present in a biological sample that comprises one or more polypeptides that are derived from the Stromelysin-1 precursor and one or more polypeptides that are derived from the Metalloproteinase inhibitor 2 precursor.

used herein, the term “72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex” refers to a polypeptide complex present in a biological sample that comprises one or more polypeptides that are derived from the 72 kDa type IV collagenase precursor and one or more polypeptides that are derived from the Metalloproteinase inhibitor 2 precursor.

The human Stromelysin-1 precursor has the following sequence (Swiss-Prot P08254 (SEQ ID NO: 2)):

        10         20         30         40 MKSLPILLLL CVAVCSAYPL DGAARGEDTS MNLVQKYLEN         50         60         70         80 YYDLKKDVKQ FVRRKDSGPV VKKIREMQKF LGLEVTGKLD         90        100        110        120 SDTLEVMRKP RCGVPDVGHF RTFPGIPKWR KTHLTYRIVN        130        140        150        160 YTPDLPKDAV DSAVEKALKV WEEVTPLTFS RLYEGEADIM        170        180        190        200 ISFAVREHGD FYPFDGPGNV LAHAYAPGPG INGDAHFDDD        210        220        230        240 EQWTKDTTGT NLFLVAAHEI GHSLGLFHSA NTEALMYPLY        250        260        270        280 HSLTDLTRFR LSQDDINGIQ SLYGPPPDSP ETPLVPTEPV        290        300        310        320 PPEPGTPANC DPALSFDAVS TLRGEILIFK DRHFWRKSLR        330        340        350        360 KLEPELHLIS SFWPSLPSGV DAAYEVTSKD LVFIFKGNQF        370        380        390        400 WAIRGNEVRA GYPRGIHTLG FPPTVRKIDA AISDKEKNKT        410        420        430        440 YFFVEDKYWR FDEKRNSMEP GFPKQIAEDF PGIDSKIDAV        450        460        470 FEEFGFFYFF TGSSQLEFDP NAKKVTHTLK SNSWLNC

The following domains have been identified in Stromelysin-1:

Residues Length Domain ID  1-17 17 signal sequence 18-99 82 propeptide 100-477 378 Stromelysin-1

The human 72 kDa type IV collagenase precursor (Swiss-Prot P08253 (SEQ ID NO: 3)) has the following sequence:

        10         20         30         40  MEALMARGAL TGPLRALCLL GCLLSHAAAA PSPIIKFPGD          50         60         70         80  VAPKTDKELA VQYLNTFYGC PKESCNLFVL KDTLKKMQKF         90        100        110        120 FGLPQTGDLD QNTIETMRKP RCGNPDVANY NFFPRKPKWD        130        140        150        160  KNQITYRIIG YTPDLDPETV DDAFARAFQV WSDVTPLRFS         170        180        190        200 RIHDGEADIM INFGRWEHGD GYPFDGKDGL LAHAFAPGTG        210        220        230        240 VGGDSHFDDD ELWTLGEGQV VRVKYGNADG EYCKFPFLFN        250        260        270        280 GKEYNSCTDT GRSDGFLWCS TTYNFEKDGK YGFCPHEALF        290        300        310        320 TMGGNAEGQP CKFPFRFQGT SYDSCTTEGR TDGYRWCGTT        330        340        350        360 EDYDRDKKYG FCPETAMSTV GGNSEGAPCV FPFTFLGNKY        370        380        390        400 ESCTSAGRSD GKMWCATTAN YDDDRKWGFC PDQGYSLFLV        410        420        430        440 AAHEFGHAMG LEHSQDPGAL MAPIYTYTKN FRLSQDDIKG        450        460        470        480 IQELYGASPD IDLGTGPTPT LGPVTPEICK QDIVFDGIAQ        490        500        510        520 IRGEIFFFKD RFIWRTVTPR DKPMGPLLVA TFWPELPEKI        530        540        550        560 DAVYEAPQEE KAVFFAGNEY WIYSASTLER GYPKPLTSLG        570        580        590        600 LPPDVQRVDA AFNWSKNKKT YIFAGDKFWR YNEVKKKMDP        610        620        630        640 GFPKLIADAW NAIPDNLDAV VDLQGGGHSY FFKGAYYLKL        650        660 ENQSLKSVKF GSIKSDWLGC

The following domains have been identified in 72 kDa type IV collagenase:

Residues Length Domain ID 1-29 29 Signal peptide 30-109 90 Activation peptide 110-660  551 72 kDa type IV collagenase (4-73)

The human Metalloproteinase inhibitor 2 precursor (Swiss-Prot P16035 (SEQ ID NO: 4)) has the following sequence:

        10         20         30         40 MGAAARTLRL ALGLLLLATL LRPADACSCS PVHPQQAFCN         50         60         70         80 ADVVIRAKAV SEKEVDSGND IYGNPIKRIQ YEIKQIKMFK         90        100        110        120 GPEKDIEFIY TAPSSAVCGV SLDVGGKKEY LIAGKAEGDG        130        140        150        160 KMHITLCDFI VPWDTLSTTQ KKSLNHRYQM GCECKITRCP        170        180        190        200 MIPCYISSPD ECLWMDWVTE KNINGHQAKF FACIKRSDGS        210        220 CAWYRGAAPP KQEFLDIEDP

The following domains have been identified in Metalloproteinase inhibitor 2:

Residues Length Domain ID 1-26 26 Signal peptide 27-220 194 Metalloproteinase inhibitor 2

As used herein, the term “Insulin-like growth factor 1 receptor” refers to one or more polypeptides present in a biological sample that are derived from the Insulin-like growth factor 1 receptor precursor (Swiss-Prot P08069 (SEQ ID NO: 5)).

        10         20         30         40         50         60 MKSGSGGGSP TSLWGLLFLS AALSLWPTSG EICGPGIDIR NDYQQLKRLE NCTVIEGYLH         70         80         90        100        110        120 ILLISKAEDY RSYRFPKLTV ITEYLLLFRV AGLESLGDLF PNLTVIRGWK LFYNYALVIF        130        140        150        160        170        180 EMTNLKDIGL YNLRNITRGA IRIEKNADLC YLSTVDWSLI LDAVSNNYIV GNKPPKECGD        190        200        210        220        230        240 LCPGTMEEKP MCEKTTINNE YNYRCWTTNR CQKMCPSTCG KRACTENNEC CHPECLGSCS        250        260        270        280        290        300 APDNDTACVA CRHYYYAGVC VPACPPNTYR FEGWRCVDRD FCANILSAES SDSEGFVIHD        310        320        330        340        350        360 GECMQECPSG FIRNGSQSMY CIPCEGPCPK VCEEEKKTKT IDSVTSAQML QGCTIFKGNL        370        380        390        400        410        420 LINIRRGNNI ASELENFMGL IEVVTGYVKI RHSHALVSLS FLKNLRLILG EEQLEGNYSF        430        440        450        460        470        480 YVLDNQNLQQ LWDWDHRNLT IKAGKMYFAF NPKLCVSEIY RMEEVTGTKG RQSKGDINTR        490        500        510        520        530        540 NNGERASCES DVLHFTSTTT SKNRIIITWH RYRPPDYRDL ISFTVYYKEA PFKNVTEYDG        550        560        570        580        590        600 QDACGSNSWN MVDVDLPPNK DVEPGILLHG LKPWTQYAVY VKAVTLTMVE NDHIRGAKSE        610        620        630        640        650        660 ILYIRTNASV PSIPLDVLSA SNSSSQLIVK WNPPSLPNGN LSYYIVRWQR QPQDGYLYRH        670        680        690        700        710        720 NYCSKDKIPI RKYADGTIDI EEVTENPKTE VCGGEKGPCC ACPKTEAEKQ AEKEEAEYRK        730        740        750        760        770        780 VFENFLHNSI FVPRPERKRR DVMQVANTTM SSRSRNTTAA DTYNITDPEE LETEYPFFES        790        800        810        820        830        840 RVDNKERTVI SNLRPFTLYR IDIHSCNHEA EKLGCSASNF VFARTMPAEG ADDIPGPVTW        850        860        870        880        890        900 EPRPENSIFL KWPEPENPNG LILMYEIKYG SQVEDQRECV SRQEYRKYGG AKLNRLNPGN        910        920        930        940        950        960 YTARIQATSL SGNGSWTDPV FFYVQAKTGY ENFIHLIIAL PVAVLLIVGG LVIMLYVFHR        970        980        990       1000       1010       1020 KRNNSRLGNG VLYASVNPEY FSAADVYVPD EWEVAREKIT MSRELGQGSF GMVYEGVAKG       1030       1040       1050       1060       1070       1080 VVKDEPETRV AIKTVNEAAS MRERIEFLNE ASVMKEFNCH HVVRLLGVVS QGQPTLVIME       1090       1100       1110       1120       1130       1140 LMTRGDLKSY LRSLRPEMEN NPVLAPPSLS KMIQMAGEIA DGMAYLNANK FVHRDLAARN       1150       1160       1170       1180       1190       1200 CMVAEDFTVK IGDFGMTRDI YETDYYRKGG KGLLPVRWMS PESLKDGVFT TYSDVWSFGV       1210       1220       1230       1240       1250       1260 VLWEIATLAE QPYQGLSNEQ VLRFVMEGGL LDKPDNCPDM LFELMRMCWQ YNPKMRPSFL       1270       1280       1290       1300       1310       1320 EIISSIKEEM EPGFREVSFY YSEENKLPEP EELDLEPENM ESVPLDPSAS SSSLPLPDRH       1330       1340       1350       1360 SGHKAENGPG PGVLVLRASF DERQPYAHMN GGRKNERALP LPQSSTC

Most preferably, the Insulin-like growth factor 1 receptor assay detects one or more soluble forms of Insulin-like growth factor 1 receptor. Insulin-like growth factor 1 receptor is a single-pass type I membrane protein having a large extracellular domain, most or all of which is present in soluble forms of Insulin-like growth factor 1 receptor generated either through alternative splicing event which deletes all or a portion of the transmembrane domain, or by proteolysis of the membrane-bound form. In the case of an immunoassay, one or more antibodies that bind to epitopes within this extracellular domain may be used to detect these soluble form(s). The following domains have been identified in Insulin-like growth factor 1 receptor:

Residues Length Domain ID 1-30 30 signal sequence 31-736 706 Insulin-like growth factor 1 receptor alpha chain (extracellular) 741-1367 627 Insulin-like growth factor 1 receptor beta chain 741-935  195 extracellular 936-959  24 transmembrane 960-1367 408 cytoplasmic

As used herein, the term “myeloid differentiation primary response protein MyD88” refers to one or more polypeptides present in a biological sample that are derived from the myeloid differentiation primary response protein MyD88 precursor (Swiss-Prot Q99836 (SEQ ID NO: 6)).

        10         20         30         40 MAAGGPGAGS AAPVSSTSSL PLAALNMRVR RRLSLFLNVR         50         60         70         80 TQVAADWTAL AEEMDFEYLE IRQLETQADP TGRLLDAWQG         90        100        110        120 RPGASVGRLL ELLTKLGRDD VLLELGPSIE EDCQKYILKQ        130        140        150        160 QQEEAEKPLQ VAAVDSSVPR TAELAGITTL DDPLGHMPER        170        180        190        200 FDAFICYCPS DIQFVQEMIR QLEQTNYRLK LCVSDRDVLP        210        220        230        240 GTCVWSIASE LIEKRCRRMV VVVSDDYLQS KECDFQTKFA        250        260        270        280 LSLSPGAHQK RLIPIKYKAM KKEFPSILRF ITVCDYTNPC        290 TKSWFWTRLA KALSLP

As used herein, the term “neuronal cell adhesion molecule” refers to one or more polypeptides present in a biological sample that are derived from the neuronal cell adhesion molecule precursor (Swiss-Prot Q92823 (SEQ ID NO: 7)).

        10         20         30         40         50         60 MQLKIMPKKK RLSAGRVPLI LFLCQMISAL EVPLDPKLLE DLVQPPTITQ QSPKDYIIDP         70         80         90        100        110        120 RENIVIQCEA KGKPPPSFSW TRNGTHFDID KDPLVTMKPG TGILIINIMS EGKAETYEGV        130        140        150        160        170        180 YQCTARNERG AAVSNNIVVR PSRSPLWTKE KLEPITLQSG QSLVLPCRPP IGLPPPIIFW        190        200        210        220        230        240 MDNSFQRLPQ SERVSQGLNG DLYFSNVLPE DTREDYICYA RFNHTQTIQQ KQPISVKVIS        250        260        270        280        290        300 VDELNDTIAA NLSDTEFYGA KSSRERPPTF LTPEGNASNK EELRGNVLSL ECIAEGLPTP        310        320        330        340        350        360 IIYWAKEDGM LPKNRTVYKN FEKTLQIIHV SEADSGNYQC IAKNALGAIH HTISVRVKAA        370        380        390        400        410        420 PYWITAPQNL VLSPGEDGTL ICRANGNPKP RISWLTNGVP IEIAPDDPSR KIDGDTIIFS        430        440        450        460        470        480 NVQERSSAVY QCNASNEYGY LLANAFVNVL AEPPRILTPA NTLYQVIANR PALLDCAFFG        490        500        510        520        530        540 SPLPTIEWFK GAKGSALHED IYVLHENGTL EIPVAQKDST GTYTCVARNK LGMAKNEVHL        550        560        570        580        590        600 EIKDPTWIVK QPEYAVVQRG SMVSFECKVK HDHTLSLTVL WLKDNRELPS DERFTVDKDH        610        620        630        640        650        660 LVVADVSDDD SGTYTCVANT TLDSVSASAV LSVVAPTPTP APVYDVPNPP FDLELTDQLD        670        680        690        700        710        720 KSVQLSWTPG DDNNSPITKF IIEYEDAMHK PGLWHHQTEV SGTQTTAQLK LSPYVNYSFR        730        740        750        760        770        780 VMAVNSIGKS LPSEASEQYL TKASEPDKNP TAVEGLGSEP DNLVITWKPL NGFESNGPGL        790        800        810        820        830        840 QYKVSWRQKD GDDEWTSVVV ANVSKYIVSG TPTFVPYLIK VQALNDMGFA PEPAVVMGHS        850        860        870        880        890        900 GEDLPMVAPG NVRVNVVNST LAEVHWDPVP LKSIRGHLQG YRIYYWKTQS SSKRNRRHIE        910        920        930        940        950        960 KKILTFQGSK THGMLPGLEP FSHYTLNVRV VNGKGEGPAS PDRVFNTPEG VPSAPSSLKI        970        980        990       1000       1010       1020 VNPTLDSLTL EWDPPSHPNG ILTEYTLKYQ PINSTHELGP LVDLKIPANK TRWTLKNLNF       1030       1040       1050       1060       1070       1080 STRYKFYFYA QTSAGSGSQI TEEAVTTVDE AGILPPDVGA GKVQAVNTRI SNLTAAAAET       1090       1100       1110       1120       1130       1140 YANISWEYEG PEHVNFYVEY GVAGSKEEWR KEIVNGSRSF FGLKGLMPGT AYKVRVGAVG       1150       1160       1170       1180       1190       1200 DSGFVSSEDV FETGPAMASR QVDIATQGWF IGLMCAVALL ILILLIVCFI RRNKGGKYPV       1210       1220       1230       1240       1250       1260 KEKEDAHADP EIQPMKEDDG TFGEYSDAED HKPLKKGSRT PSDRTVKKED SDDSLVDYGE       1270       1280       1290       1300 GVNGQFNEDG SFIGQYSGKK EKEPAEGNES SEAPSPVNAM NSFV

Most preferably, the neuronal cell adhesion molecule assay detects one or more soluble forms of neuronal cell adhesion molecule. The Neuronal cell adhesion molecule precursor encodes a single-pass type I membrane protein having a large extracellular domain, most or all of which is present in soluble forms of neuronal cell adhesion molecule generated either through alternative splicing event which deletes all or a portion of the transmembrane domain, or by proteolysis of the membrane-bound form. In the case of an immunoassay, one or more antibodies that bind to epitopes within this extracellular domain may be used to detect these soluble form(s). The following domains have been identified in neuronal cell adhesion molecule:

Residues Length Domain ID  1-24 24 signal sequence  25-1304 1280 neuronal cell adhesion molecule  25-1167 1143 extracellular 1168-1190 23 transmembrane 1191-1304 114 cytoplasmic

As used herein, the term “Tumor necrosis factor ligand superfamily member 10” refers to one or more polypeptides present in a biological sample that are derived from the Tumor necrosis factor ligand superfamily member 10 precursor (Swiss-Prot P50591 (SEQ ID NO: 8))

        10         20         30         40 MAMMEVQGGP SLGQTCVLIV IFTVLLQSLC VAVTYVYFTN         50         60         70         80 ELKQMQDKYS KSGIACFLKE DDSYWDPNDE ESMNSPCWQV         90        100        110        120 KWQLRQLVRK MILRTSEETI STVQEKQQNI SPLVRERGPQ        130        140        150        160 RVAAHITGTR GRSNTLSSPN SKNEKALGRK INSWESSRSG        170        180        190        200 HSFLSNLHLR NGELVIHEKG FYYIYSQTYF RFQEEIKENT        210        220        230        240 KNDKQMVQYI YKYTSYPDPI LLMKSARNSC WSKDAEYGLY        250        260        270        280 SIYQGGIFEL KENDRIFVSV TNEHLIDMDH EASFFGAFLV G

This protein is also known as TRAIL and APO2L. Most preferably, the Tumor necrosis factor ligand superfamily member 10 precursor assay detects one or more soluble forms of Tumor necrosis factor ligand superfamily member 10 precursor. The Tumor necrosis factor ligand superfamily member 10 precursor encodes a single-pass type II membrane protein having a large extracellular domain, most or all of which is present in soluble forms of Tumor necrosis factor ligand superfamily member 10 precursor generated either through alternative splicing event which deletes all or a portion of the transmembrane domain, or by proteolysis of the membrane-bound form. In the case of an immunoassay, one or more antibodies that bind to epitopes within this extracellular domain may be used to detect these soluble form(s). The following domains have been identified in Tumor necrosis factor ligand superfamily member 10 precursor:

Residues Length Domain ID  1-281 281 Tumor necrosis factor ligand superfamily member 10 1-17 17 cytoplasmic domain 18-38  21 Signal-anchor for type II membrane protein 39-281 243 extracellular domain

As used herein, the term “alpha-1-antitrypsin:leukocyte elastase complex” refers to a polypeptide complex present in a biological sample that comprises one or more polypeptides that are derived from the alpha-1-antitrypsin precursor and one or more polypeptides that are derived from the leukocyte elastase precursor.

The human alpha-1-antitrypsin precursor has the following sequence (Swiss-Prot P01009 (SEQ ID NO: 9)):

        10         20         30         40 MPSSVSWGIL LLAGLCCLVP VSLAEDPQGD AAQKTDTSHH         50         60         70         80 DQDHPTFNKI TPNLAEFAFS LYRQLAHQSN STNIFFSPVS         90        100        110        120 IATAFAMLSL GTKADTHDEI LEGLNFNLTE IPEAQIHEGF        130        140        150        160 QELLRTLNQP DSQLQLTTGN GLFLSEGLKL VDKFLEDVKK        170        180        190        200 LYHSEAFTVN FGDTEEAKKQ INDYVEKGTQ GKIVDLVKEL        210        220        230        240 DRDTVFALVN YIFFKGKWER PFEVKDTEEE DFHVDQVTTV        250        260        270        280 KVPMMKRLGM FNIQHCKKLS SWVLLMKYLG NATAIFFLPD        290        300        310        320 EGKLQHLENE LTHDIITKFL ENEDRRSASL HLPKLSITGT        330        340        350        360 YDLKSVLGQL GITKVFSNGA DLSGVTEEAP LKLSKAVHKA        370        380        390        400 VLTIDEKGTE AAGAMFLEAI PMSIPPEVKF NKPFVFLMIE         410 QNTKSPLFMG KVVNPTQK

The following domains have been identified in alpha-1-antitrypsin:

Residues Length Domain ID 1-24 24 signal sequence 25-418 394 alpha-1-antitrypsin

The human leukocyte elastase precursor (Swiss-Prot P08246 (SEQ ID NO: 10)) has the following sequence:

        10         20         30         40 MTLGRRLACL FLACVLPALL LGGTALASEI VGGRRARPHA         50         60         70         80 WPFMVSLQLR GGHFCGATLI APNFVMSAAH CVANVNVRAV         90        100        110        120 RVVLGAHNLS RREPTRQVFA VQRIFENGYD PVNLLNDIVI        130        140        150        160 LQLNGSATIN ANVQVAQLPA QGRRLGNGVQ CLAMGWGLLG        170        180        190        200 RNRGIASVLQ ELNVTVVTSL CRRSNVCTLV RGRQAGVCFG        210        220        230        240 DSGSPLVCNG LIHGIASFVR GGCASGLYPD AFAPVAQFVN        250        260 WIDSIIQRSE DNPCPHPRDP DPASRTH

The following domains have been identified in leukocyte elastase:

Residues Length Domain ID 1-27 315 signal sequence 28-29  2 pro-peptide 30-267 238 leukocyte elastase

As used herein, the term “relating a signal to the presence or amount” of an analyte reflects the following understanding. Assay signals are typically related to the presence or amount of an analyte through the use of a standard curve calculated using known concentrations of the analyte of interest. As the term is used herein, an assay is “configured to detect” an analyte if an assay can generate a detectable signal indicative of the presence or amount of a physiologically relevant concentration of the analyte. Because an antibody epitope is on the order of 8 amino acids, an immunoassay configured to detect a marker of interest will also detect polypeptides related to the marker sequence, so long as those polypeptides contain the epitope(s) necessary to bind to the antibody or antibodies used in the assay. The term “related marker” as used herein with regard to a biomarker such as one of the kidney injury markers described herein refers to one or more fragments, variants, etc., of a particular marker or its biosynthetic parent that may be detected as a surrogate for the marker itself or as independent biomarkers. The term also refers to one or more polypeptides present in a biological sample that are derived from the biomarker precursor complexed to additional species, such as binding proteins, receptors, heparin, lipids, sugars, etc.

In this regard, the skilled artisan will understand that the signals obtained from an immunoassay are a direct result of complexes formed between one or more antibodies and the target biomolecule (i.e., the analyte) and polypeptides containing the necessary epitope(s) to which the antibodies bind. While such assays may detect the full length biomarker and the assay result be expressed as a concentration of a biomarker of interest, the signal from the assay is actually a result of all such “immunoreactive” polypeptides present in the sample. Expression of biomarkers may also be determined by means other than immunoassays, including protein measurements (such as dot blots, western blots, chromatographic methods, mass spectrometry, etc.) and nucleic acid measurements (mRNA quatitation). This list is not meant to be limiting.

The term “positive going” marker as that term is used herein refer to a marker that is determined to be elevated in subjects suffering from a disease or condition, relative to subjects not suffering from that disease or condition. The term “negative going” marker as that term is used herein refer to a marker that is determined to be reduced in subjects suffering from a disease or condition, relative to subjects not suffering from that disease or condition.

The term “subject” as used herein refers to a human or non-human organism. Thus, the methods and compositions described herein are applicable to both human and veterinary disease. Further, while a subject is preferably a living organism, the invention described herein may be used in post-mortem analysis as well. Preferred subjects are humans, and most preferably “patients,” which as used herein refers to living humans that are receiving medical care for a disease or condition. This includes persons with no defined illness who are being investigated for signs of pathology.

Preferably, an analyte is measured in a sample. Such a sample may be obtained from a subject, or may be obtained from biological materials intended to be provided to the subject. For example, a sample may be obtained from a kidney being evaluated for possible transplantation into a subject, and an analyte measurement used to evaluate the kidney for preexisting damage. Preferred samples are body fluid samples.

The term “body fluid sample” as used herein refers to a sample of bodily fluid obtained for the purpose of diagnosis, prognosis, classification or evaluation of a subject of interest, such as a patient or transplant donor. In certain embodiments, such a sample may be obtained for the purpose of determining the outcome of an ongoing condition or the effect of a treatment regimen on a condition. Preferred body fluid samples include blood, serum, plasma, cerebrospinal fluid, urine, saliva, sputum, and pleural effusions. In addition, one of skill in the art would realize that certain body fluid samples would be more readily analyzed following a fractionation or purification procedure, for example, separation of whole blood into serum or plasma components.

The term “diagnosis” as used herein refers to methods by which the skilled artisan can estimate and/or determine the probability (“a likelihood”) of whether or not a patient is suffering from a given disease or condition. In the case of the present invention, “diagnosis” includes using the results of an assay, most preferably an immunoassay, for a kidney injury marker of the present invention, optionally together with other clinical characteristics, to arrive at a diagnosis (that is, the occurrence or nonoccurrence) of an acute renal injury or ARF for the subject from which a sample was obtained and assayed. That such a diagnosis is “determined” is not meant to imply that the diagnosis is 100% accurate. Many biomarkers are indicative of multiple conditions. The skilled clinician does not use biomarker results in an informational vacuum, but rather test results are used together with other clinical indicia to arrive at a diagnosis. Thus, a measured biomarker level on one side of a predetermined diagnostic threshold indicates a greater likelihood of the occurrence of disease in the subject relative to a measured level on the other side of the predetermined diagnostic threshold.

Similarly, a prognostic risk signals a probability (“a likelihood”) that a given course or outcome will occur. A level or a change in level of a prognostic indicator, which in turn is associated with an increased probability of morbidity (e.g., worsening renal function, future ARF, or death) is referred to as being “indicative of an increased likelihood” of an adverse outcome in a patient.

Marker Assays

In general, immunoassays involve contacting a sample containing or suspected of containing a biomarker of interest with at least one antibody that specifically binds to the biomarker. A signal is then generated indicative of the presence or amount of complexes formed by the binding of polypeptides in the sample to the antibody. The signal is then related to the presence or amount of the biomarker in the sample. Numerous methods and devices are well known to the skilled artisan for the detection and analysis of biomarkers. See, e.g., U.S. Pat. Nos. 6,143,576; 6,113,855; 6,019,944; 5,985,579; 5,947,124; 5,939,272; 5,922,615; 5,885,527; 5,851,776; 5,824,799; 5,679,526; 5,525,524; and 5,480,792, and The Immunoassay Handbook, David Wild, ed. Stockton Press, New York, 1994, each of which is hereby incorporated by reference in its entirety, including all tables, figures and claims.

The assay devices and methods known in the art can utilize labeled molecules in various sandwich, competitive, or non-competitive assay formats, to generate a signal that is related to the presence or amount of the biomarker of interest. Suitable assay formats also include chromatographic, mass spectrographic, and protein “blotting” methods. Additionally, certain methods and devices, such as bio sensors and optical immunoassays, may be employed to determine the presence or amount of analytes without the need for a labeled molecule. See, e.g., U.S. Pat. Nos. 5,631,171; and 5,955,377, each of which is hereby incorporated by reference in its entirety, including all tables, figures and claims. One skilled in the art also recognizes that robotic instrumentation including but not limited to Beckman ACCESS®, Abbott AXSYM®, Roche ELECSYS®, Dade Behring STRATUS® systems are among the immunoassay analyzers that are capable of performing immunoassays. But any suitable immunoassay may be utilized, for example, enzyme-linked immunoassays (ELISA), radioimmunoassays (RIAs), competitive binding assays, and the like.

Antibodies or other polypeptides may be immobilized onto a variety of solid supports for use in assays. Solid phases that may be used to immobilize specific binding members include include those developed and/or used as solid phases in solid phase binding assays. Examples of suitable solid phases include membrane filters, cellulose-based papers, beads (including polymeric, latex and paramagnetic particles), glass, silicon wafers, microparticles, nanoparticles, TentaGels, AgroGels, PEGA gels, SPOCC gels, and multiple-well plates. An assay strip could be prepared by coating the antibody or a plurality of antibodies in an array on solid support. This strip could then be dipped into the test sample and then processed quickly through washes and detection steps to generate a measurable signal, such as a colored spot. Antibodies or other polypeptides may be bound to specific zones of assay devices either by conjugating directly to an assay device surface, or by indirect binding. In an example of the later case, antibodies or other polypeptides may be immobilized on particles or other solid supports, and that solid support immobilized to the device surface.

Biological assays require methods for detection, and one of the most common methods for quantitation of results is to conjugate a detectable label to a protein or nucleic acid that has affinity for one of the components in the biological system being studied. Detectable labels may include molecules that are themselves detectable (e.g., fluorescent moieties, electrochemical labels, metal chelates, etc.) as well as molecules that may be indirectly detected by production of a detectable reaction product (e.g., enzymes such as horseradish peroxidase, alkaline phosphatase, etc.) or by a specific binding molecule which itself may be detectable (e.g., biotin, digoxigenin, maltose, oligohistidine, 2,4-dintrobenzene, phenylarsenate, ssDNA, dsDNA, etc.).

Preparation of solid phases and detectable label conjugates often comprise the use of chemical cross-linkers. Cross-linking reagents contain at least two reactive groups, and are divided generally into homofunctional cross-linkers (containing identical reactive groups) and heterofunctional cross-linkers (containing non-identical reactive groups). Homobifunctional cross-linkers that couple through amines, sulfhydryls or react non-specifically are available from many commercial sources. Maleimides, alkyl and aryl halides, alpha-haloacyls and pyridyl disulfides are thiol reactive groups. Maleimides, alkyl and aryl halides, and alpha-haloacyls react with sulfhydryls to form thiol ether bonds, while pyridyl disulfides react with sulfhydryls to produce mixed disulfides. The pyridyl disulfide product is cleavable. Imidoesters are also very useful for protein-protein cross-links. A variety of heterobifunctional cross-linkers, each combining different attributes for successful conjugation, are commercially available.

In certain aspects, the present invention provides kits for the analysis of the described kidney injury markers. The kit comprises reagents for the analysis of at least one test sample which comprise at least one antibody that a kidney injury marker. The kit can also include devices and instructions for performing one or more of the diagnostic and/or prognostic correlations described herein. Preferred kits will comprise an antibody pair for performing a sandwich assay, or a labeled species for performing a competitive assay, for the analyte. Preferably, an antibody pair comprises a first antibody conjugated to a solid phase and a second antibody conjugated to a detectable label, wherein each of the first and second antibodies that bind a kidney injury marker. Most preferably each of the antibodies are monoclonal antibodies. The instructions for use of the kit and performing the correlations can be in the form of labeling, which refers to any written or recorded material that is attached to, or otherwise accompanies a kit at any time during its manufacture, transport, sale or use. For example, the term labeling encompasses advertising leaflets and brochures, packaging materials, instructions, audio or video cassettes, computer discs, as well as writing imprinted directly on kits.

Antibodies

The term “antibody” as used herein refers to a peptide or polypeptide derived from, modeled after or substantially encoded by an immunoglobulin gene or immunoglobulin genes, or fragments thereof, capable of specifically binding an antigen or epitope. See, e.g. Fundamental Immunology, 3rd Edition, W. E. Paul, ed., Raven Press, N.Y. (1993); Wilson (1994; J. Immunol. Methods 175:267-273; Yarmush (1992) J. Biochem. Biophys. Methods 25:85-97. The term antibody includes antigen-binding portions, i.e., “antigen binding sites,” (e.g., fragments, subsequences, complementarity determining regions (CDRs)) that retain capacity to bind antigen, including (i) a Fab fragment, a monovalent fragment consisting of the VL, VH, CL and CH1 domains; (ii) a F(ab′)2 fragment, a bivalent fragment comprising two Fab fragments linked by a disulfide bridge at the hinge region; (iii) a Fd fragment consisting of the VH and CH1 domains; (iv) a Fv fragment consisting of the VL and VH domains of a single arm of an antibody, (v) a dAb fragment (Ward et al., (1989) Nature 341:544-546), which consists of a VH domain; and (vi) an isolated complementarity determining region (CDR). Single chain antibodies are also included by reference in the term “antibody.”

Antibodies used in the immunoassays described herein preferably specifically bind to a kidney injury marker of the present invention. The term “specifically binds” is not intended to indicate that an antibody binds exclusively to its intended target since, as noted above, an antibody binds to any polypeptide displaying the epitope(s) to which the antibody binds. Rather, an antibody “specifically binds” if its affinity for its intended target is about 5-fold greater when compared to its affinity for a non-target molecule which does not display the appropriate epitope(s). Preferably the affinity of the antibody will be at least about 5 fold, preferably 10 fold, more preferably 25-fold, even more preferably 50-fold, and most preferably 100-fold or more, greater for a target molecule than its affinity for a non-target molecule. In preferred embodiments, Preferred antibodies bind with affinities of at least about 10⁷ M⁻¹, and preferably between about 10⁸ M⁻¹ to about 10⁹ M⁻¹, about 10⁹ M⁻¹ to about 10¹⁰ M⁻¹, or about 10¹⁰ M⁻¹ to about 10¹²M⁻¹.

Affinity is calculated as K_(d)=k_(off)/k_(on) (k_(off) is the dissociation rate constant, K_(on) is the association rate constant and K_(d) is the equilibrium constant). Affinity can be determined at equilibrium by measuring the fraction bound (r) of labeled ligand at various concentrations (c). The data are graphed using the Scatchard equation: r/c=K(n−r): where r=moles of bound ligand/mole of receptor at equilibrium; c=free ligand concentration at equilibrium; K=equilibrium association constant; and n=number of ligand binding sites per receptor molecule. By graphical analysis, r/c is plotted on the Y-axis versus r on the X-axis, thus producing a Scatchard plot. Antibody affinity measurement by Scatchard analysis is well known in the art. See, e.g., van Erp et al., J. Immunoassay 12: 425-43, 1991; Nelson and Griswold, Comput. Methods Programs Biomed. 27: 65-8, 1988.

The term “epitope” refers to an antigenic determinant capable of specific binding to an antibody. Epitopes usually consist of chemically active surface groupings of molecules such as amino acids or sugar side chains and usually have specific three dimensional structural characteristics, as well as specific charge characteristics. Conformational and nonconformational epitopes are distinguished in that the binding to the former but not the latter is lost in the presence of denaturing solvents.

Numerous publications discuss the use of phage display technology to produce and screen libraries of polypeptides for binding to a selected analyte. See, e.g, Cwirla et al., Proc. Natl. Acad. Sci. USA 87, 6378-82, 1990; Devlin et al., Science 249, 404-6, 1990, Scott and Smith, Science 249, 386-88, 1990; and Ladner et al., U.S. Pat. No. 5,571,698. A basic concept of phage display methods is the establishment of a physical association between DNA encoding a polypeptide to be screened and the polypeptide. This physical association is provided by the phage particle, which displays a polypeptide as part of a capsid enclosing the phage genome which encodes the polypeptide. The establishment of a physical association between polypeptides and their genetic material allows simultaneous mass screening of very large numbers of phage bearing different polypeptides. Phage displaying a polypeptide with affinity to a target bind to the target and these phage are enriched by affinity screening to the target. The identity of polypeptides displayed from these phage can be determined from their respective genomes. Using these methods a polypeptide identified as having a binding affinity for a desired target can then be synthesized in bulk by conventional means. See, e.g., U.S. Pat. No. 6,057,098, which is hereby incorporated in its entirety, including all tables, figures, and claims.

The antibodies that are generated by these methods may then be selected by first screening for affinity and specificity with the purified polypeptide of interest and, if required, comparing the results to the affinity and specificity of the antibodies with polypeptides that are desired to be excluded from binding. The screening procedure can involve immobilization of the purified polypeptides in separate wells of microtiter plates. The solution containing a potential antibody or groups of antibodies is then placed into the respective microtiter wells and incubated for about 30 min to 2 h. The microtiter wells are then washed and a labeled secondary antibody (for example, an anti-mouse antibody conjugated to alkaline phosphatase if the raised antibodies are mouse antibodies) is added to the wells and incubated for about 30 min and then washed. Substrate is added to the wells and a color reaction will appear where antibody to the immobilized polypeptide(s) are present.

The antibodies so identified may then be further analyzed for affinity and specificity in the assay design selected. In the development of immunoassays for a target protein, the purified target protein acts as a standard with which to judge the sensitivity and specificity of the immunoassay using the antibodies that have been selected. Because the binding affinity of various antibodies may differ; certain antibody pairs (e.g., in sandwich assays) may interfere with one another sterically, etc., assay performance of an antibody may be a more important measure than absolute affinity and specificity of an antibody.

While the present application describes antibody-based binding assays in detail, alternatives to antibodies as binding species in assays are well known in the art. These include receptors for a particular target, aptamers, etc. Aptamers are oligonucleic acid or peptide molecules that bind to a specific target molecule. Aptamers are usually created by selecting them from a large random sequence pool, but natural aptamers also exist. High-affinity aptamers containing modified nucleotides conferring improved characteristics on the ligand, such as improved in vivo stability or improved delivery characteristics. Examples of such modifications include chemical substitutions at the ribose and/or phosphate and/or base positions, and may include amino acid side chain functionalities.

Assay Correlations

The term “correlating” as used herein in reference to the use of biomarkers refers to comparing the presence or amount of the biomarker(s) in a patient to its presence or amount in persons known to suffer from, or known to be at risk of, a given condition; or in persons known to be free of a given condition. Often, this takes the form of comparing an assay result in the form of a biomarker concentration to a predetermined threshold selected to be indicative of the occurrence or nonoccurrence of a disease or the likelihood of some future outcome.

Selecting a diagnostic threshold involves, among other things, consideration of the probability of disease, distribution of true and false diagnoses at different test thresholds, and estimates of the consequences of treatment (or a failure to treat) based on the diagnosis. For example, when considering administering a specific therapy which is highly efficacious and has a low level of risk, few tests are needed because clinicians can accept substantial diagnostic uncertainty. On the other hand, in situations where treatment options are less effective and more risky, clinicians often need a higher degree of diagnostic certainty. Thus, cost/benefit analysis is involved in selecting a diagnostic threshold.

Suitable thresholds may be determined in a variety of ways. For example, one recommended diagnostic threshold for the diagnosis of acute myocardial infarction using cardiac troponin is the 97.5th percentile of the concentration seen in a normal population. Another method may be to look at serial samples from the same patient, where a prior “baseline” result is used to monitor for temporal changes in a biomarker level.

Population studies may also be used to select a decision threshold. Reciever Operating Characteristic (“ROC”) arose from the field of signal dectection theory developed during World War II for the analysis of radar images, and ROC analysis is often used to select a threshold able to best distinguish a “diseased” subpopulation from a “nondiseased” subpopulation. A false positive in this case occurs when the person tests positive, but actually does not have the disease. A false negative, on the other hand, occurs when the person tests negative, suggesting they are healthy, when they actually do have the disease. To draw a ROC curve, the true positive rate (TPR) and false positive rate (FPR) are determined as the decision threshold is varied continuously. Since TPR is equivalent with sensitivity and FPR is equal to 1—specificity, the ROC graph is sometimes called the sensitivity vs (1—specificity) plot. A perfect test will have an area under the ROC curve of 1.0; a random test will have an area of 0.5. A threshold is selected to provide an acceptable level of specificity and sensitivity.

In this context, “diseased” is meant to refer to a population having one characteristic (the presence of a disease or condition or the occurrence of some outcome) and “nondiseased” is meant to refer to a population lacking the characteristic. While a single decision threshold is the simplest application of such a method, multiple decision thresholds may be used. For example, below a first threshold, the absence of disease may be assigned with relatively high confidence, and above a second threshold the presence of disease may also be assigned with relatively high confidence. Between the two thresholds may be considered indeterminate. This is meant to be exemplary in nature only.

In addition to threshold comparisons, other methods for correlating assay results to a patient classification (occurrence or nonoccurrence of disease, likelihood of an outcome, etc.) include decision trees, rule sets, Bayesian methods, and neural network methods. These methods can produce probability values representing the degree to which a subject belongs to one classification out of a plurality of classifications.

Measures of test accuracy may be obtained as described in Fischer et al., Intensive Care Med. 29: 1043-51, 2003, and used to determine the effectiveness of a given biomarker. These measures include sensitivity and specificity, predictive values, likelihood ratios, diagnostic odds ratios, and ROC curve areas. The area under the curve (“AUC”) of a ROC plot is equal to the probability that a classifier will rank a randomly chosen positive instance higher than a randomly chosen negative one. The area under the ROC curve may be thought of as equivalent to the Mann-Whitney U test, which tests for the median difference between scores obtained in the two groups considered if the groups are of continuous data, or to the Wilcoxon test of ranks.

As discussed above, suitable tests may exhibit one or more of the following results on these various measures: a specificity of greater than 0.5, preferably at least 0.6, more preferably at least 0.7, still more preferably at least 0.8, even more preferably at least 0.9 and most preferably at least 0.95, with a corresponding sensitivity greater than 0.2, preferably greater than 0.3, more preferably greater than 0.4, still more preferably at least 0.5, even more preferably 0.6, yet more preferably greater than 0.7, still more preferably greater than 0.8, more preferably greater than 0.9, and most preferably greater than 0.95; a sensitivity of greater than 0.5, preferably at least 0.6, more preferably at least 0.7, still more preferably at least 0.8, even more preferably at least 0.9 and most preferably at least 0.95, with a corresponding specificity greater than 0.2, preferably greater than 0.3, more preferably greater than 0.4, still more preferably at least 0.5, even more preferably 0.6, yet more preferably greater than 0.7, still more preferably greater than 0.8, more preferably greater than 0.9, and most preferably greater than 0.95; at least 75% sensitivity, combined with at least 75% specificity; a ROC curve area of greater than 0.5, preferably at least 0.6, more preferably 0.7, still more preferably at least 0.8, even more preferably at least 0.9, and most preferably at least 0.95; an odds ratio different from 1, preferably at least about 2 or more or about 0.5 or less, more preferably at least about 3 or more or about 0.33 or less, still more preferably at least about 4 or more or about 0.25 or less, even more preferably at least about 5 or more or about 0.2 or less, and most preferably at least about 10 or more or about 0.1 or less; a positive likelihood ratio (calculated as sensitivity/(1-specificity)) of greater than 1, at least 2, more preferably at least 3, still more preferably at least 5, and most preferably at least 10; and or a negative likelihood ratio (calculated as (1-sensitivity)/specificity) of less than 1, less than or equal to 0.5, more preferably less than or equal to 0.3, and most preferably less than or equal to 0.1

Additional clinical indicia may be combined with the kidney injury marker assay result(s) of the present invention. These include other biomarkers related to renal status. Examples include the following, which recite the common biomarker name, followed by the Swiss-Prot entry number for that biomarker or its parent: Actin (P68133); Adenosine deaminase binding protein (DPP4, P27487); Alpha-1-acid glycoprotein 1 (P02763); Alpha-1-microglobulin (P02760); Albumin (P02768); Angiotensinogenase (Renin, P00797); Annexin A2 (P07355); Beta-glucuronidase (P08236); B-2-microglobulin (P61679); Beta-galactosidase (P16278); BMP-7 (P18075); Brain natriuretic peptide (proBNP, BNP-32, NTproBNP; P16860); Calcium-binding protein Beta (S100-beta, P04271); Carbonic anhydrase (Q16790); Casein Kinase 2 (P68400); Ceruloplasmin (P00450); Clusterin (P10909); Complement C3 (P01024); Cysteine-rich protein (CYR61, 000622); Cytochrome C (P99999); Epidermal growth factor (EGF, P01133); Endothelin-1 (P05305); Exosomal Fetuin-A (P02765); Fatty acid-binding protein, heart (FABP3, P05413); Fatty acid-binding protein, liver (P07148); Ferritin (light chain, P02793; heavy chain P02794); Fructose-1,6-biphosphatase (P09467); GRO-alpha (CXCL1, (P09341); Growth Hormone (P01241); Hepatocyte growth factor (P14210); Insulin-like growth factor I (P01343); Immunoglobulin G; Immunoglobulin Light Chains (Kappa and Lambda); Interferon gamma (P01308); Lysozyme (P61626); Interleukin-lalpha (P01583); Interleukin-2 (P60568); Interleukin-4 (P60568); Interleukin-9 (P15248); Interleukin-12p40 (P29460); Interleukin-13 (P35225); Interleukin-16 (Q14005); L1 cell adhesion molecule (P32004); Lactate dehydrogenase (P00338); Leucine Aminopeptidase (P28838); Meprin A-alpha subunit (Q16819); Meprin A-beta subunit (Q16820); Midkine (P21741); MIP2-alpha (CXCL2, P19875); MMP-2 (P08253); MMP-9 (P14780); Netrin-1 (095631); Neutral endopeptidase (P08473); Osteopontin (P10451); Renal papillary antigen 1 (RPA1); Renal papillary antigen 2 (RPA2); Retinol binding protein (P09455); Ribonuclease; S100 calcium-binding protein A6 (P06703); Serum Amyloid P Component (P02743); Sodium/Hydrogen exchanger isoform (NHE3, P48764); Spermidine/spermine N1-acetyltransferase (P21673); TGF-Beta1 (P01137); Transferrin (P02787); Trefoil factor 3 (TFF3, Q07654); Toll-Like protein 4 (000206); Total protein; Tubulointerstitial nephritis antigen (Q9UJW2); Uromodulin (Tamm-Horsfall protein, P07911).

For purposes of risk stratification, Adiponectin (Q15848); Alkaline phosphatase (P05186); Aminopeptidase N (P15144); CalbindinD28k (P05937); Cystatin C (P01034); 8 subunit of FIFO ATPase (P03928); Gamma-glutamyltransferase (P19440); GSTa (alpha-glutathione-S-transferase, P08263); GSTpi (Glutathione-S-transferase P; GST class-pi; P09211); IGFBP-1 (P08833); IGFBP-2 (P18065); IGFBP-6 (P24592); Integral membrane protein 1 (Itml, P46977); Interleukin-6 (P05231); Interleukin-8 (P10145); Interleukin-18 (Q14116); IP-10 (10 kDa interferon-gamma-induced protein, P02778); IRPR (IFRD1, 000458); Isovaleryl-CoA dehydrogenase (IVD, P26440); I-TAC/CXCL11 (014625); Keratin 19 (P08727); Kim-1 (Hepatitis A virus cellular receptor 1, 043656); L-arginine:glycine amidinotransferase (P50440); Leptin (P41159); Lipocalin2 (NGAL, P80188); MCP-1 (P13500); MIG (Gamma-interferon-induced monokine Q07325); MIP-1a (P10147); MIP-3a (P78556); MIP-1beta (P13236); MIP-1d (Q16663); NAG (N-acetyl-beta-D-glucosaminidase, P54802); Organic ion transporter (OCT2, 015244); Osteoprotegerin (014788); P8 protein (060356); Plasminogen activator inhibitor 1 (PAI-1, P05121); ProANP(1-98) (P01160); Protein phosphatase 1-beta (PPI-beta, P62140); Rab GDI-beta (P50395); Renal kallikrein (Q86U61); RT1.B-1 (alpha) chain of the integral membrane protein (Q5Y7A8); Soluble tumor necrosis factor receptor superfamily member 1A (sTNFR-I, P19438); Soluble tumor necrosis factor receptor superfamily member 1B (sTNFR-II, P20333); Tissue inhibitor of metalloproteinases 3 (TIMP-3, P35625); uPAR (Q03405) may be combined with the kidney injury marker assay result(s) of the present invention.

Other clinical indicia which may be combined with the kidney injury marker assay result(s) of the present invention includes demographic information (e.g., weight, sex, age, race), medical history (e.g., family history, type of surgery, pre-existing disease such as aneurism, congestive heart failure, preeclampsia, eclampsia, diabetes mellitus, hypertension, coronary artery disease, proteinuria, renal insufficiency, or sepsis, type of toxin exposure such as NSAIDs, cyclosporines, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, or streptozotocin), clinical variables (e.g., blood pressure, temperature, respiration rate), risk scores (APACHE score, PREDICT score, TIMI Risk Score for UA/NSTEMI, Framingham Risk Score), a urine total protein measurement, a glomerular filtration rate, an estimated glomerular filtration rate, a urine production rate, a serum or plasma creatinine concentration, a renal papillary antigen 1 (RPA1) measurement; a renal papillary antigen 2 (RPA2) measurement; a urine creatinine concentration, a fractional excretion of sodium, a urine sodium concentration, a urine creatinine to serum or plasma creatinine ratio, a urine specific gravity, a urine osmolality, a urine urea nitrogen to plasma urea nitrogen ratio, a plasma BUN to creatnine ratio, and/or a renal failure index calculated as urine sodium/(urine creatinine/plasma creatinine). Other measures of renal function which may be combined with the kidney injury marker assay result(s) are described hereinafter and in Harrison's Principles of Internal Medicine, 17^(th) Ed., McGraw Hill, New York, pages 1741-1830, and Current Medical Diagnosis & Treatment 2008, 47^(th) Ed, McGraw Hill, New York, pages 785-815, each of which are hereby incorporated by reference in their entirety.

Combining assay results/clinical indicia in this manner can comprise the use of multivariate logistical regression, loglinear modeling, neural network analysis, n-of-m analysis, decision tree analysis, etc. This list is not meant to be limiting.

Diagnosis of Acute Renal Failure

As noted above, the terms “acute renal (or kidney) injury” and “acute renal (or kidney) failure” as used herein are defined in part in terms of changes in serum creatinine from a baseline value. Most definitions of ARF have common elements, including the use of serum creatinine and, often, urine output. Patients may present with renal dysfunction without an available baseline measure of renal function for use in this comparison. In such an event, one may estimate a baseline serum creatinine value by assuming the patient initially had a normal GFR. Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal (kidney) glomerular capillaries into the Bowman's capsule per unit time. Glomerular filtration rate (GFR) can be calculated by measuring any chemical that has a steady level in the blood, and is freely filtered but neither reabsorbed nor secreted by the kidneys. GFR is typically expressed in units of ml/min:

${GFR} = \frac{{Urine}\mspace{14mu}{Concentration} \times {Urine}\mspace{14mu}{Flow}}{{Plasma}\mspace{14mu}{Concentration}}$

By normalizing the GFR to the body surface area, a GFR of approximately 75-100 ml/min per 1.73 m² can be assumed. The rate therefore measured is the quantity of the substance in the urine that originated from a calculable volume of blood.

There are several different techniques used to calculate or estimate the glomerular filtration rate (GFR or eGFR). In clinical practice, however, creatinine clearance is used to measure GFR. Creatinine is produced naturally by the body (creatinine is a metabolite of creatine, which is found in muscle). It is freely filtered by the glomerulus, but also actively secreted by the renal tubules in very small amounts such that creatinine clearance overestimates actual GFR by 10-20%. This margin of error is acceptable considering the ease with which creatinine clearance is measured.

Creatinine clearance (CCr) can be calculated if values for creatinine's urine concentration (U_(Cr)), urine flow rate (V), and creatinine's plasma concentration (P_(Cr)) are known. Since the product of urine concentration and urine flow rate yields creatinine's excretion rate, creatinine clearance is also said to be its excretion rate (U_(Cr)×V) divided by its plasma concentration. This is commonly represented mathematically as:

$C_{Cr} = \frac{U_{Cr} \times V}{P_{Cr}}$ Commonly a 24 hour urine collection is undertaken, from empty-bladder one morning to the contents of the bladder the following morning, with a comparative blood test then taken:

$C_{Cr} = \frac{U_{Cr} \times 24\text{-}{hour}\mspace{14mu}{volume}}{P_{Cr} \times 24 \times 60\mspace{14mu}{mins}}$ To allow comparison of results between people of different sizes, the CCr is often corrected for the body surface area (BSA) and expressed compared to the average sized man as ml/min/1.73 m2. While most adults have a BSA that approaches 1.7 (1.6-1.9), extremely obese or slim patients should have their CCr corrected for their actual BSA:

$C_{{Cr} - {corrected}} = \frac{C_{Cr} \times 1.73}{BSA}$

The accuracy of a creatinine clearance measurement (even when collection is complete) is limited because as glomerular filtration rate (GFR) falls creatinine secretion is increased, and thus the rise in serum creatinine is less. Thus, creatinine excretion is much greater than the filtered load, resulting in a potentially large overestimation of the GFR (as much as a twofold difference). However, for clinical purposes it is important to determine whether renal function is stable or getting worse or better. This is often determined by monitoring serum creatinine alone. Like creatinine clearance, the serum creatinine will not be an accurate reflection of GFR in the non-steady-state condition of ARF. Nonetheless, the degree to which serum creatinine changes from baseline will reflect the change in GFR. Serum creatinine is readily and easily measured and it is specific for renal function.

For purposes of determining urine output on a Urine output on a mL/kg/hr basis, hourly urine collection and measurement is adequate. In the case where, for example, only a cumulative 24-h output was available and no patient weights are provided, minor modifications of the RIFLE urine output criteria have been described. For example, Bagshaw et al., Nephrol. Dial. Transplant. 23: 1203-1210, 2008, assumes an average patient weight of 70 kg, and patients are assigned a RIFLE classification based on the following: <35 mL/h (Risk), <21 mL/h (Injury) or <4 mL/h (Failure).

Selecting a Treatment Regimen

Once a diagnosis is obtained, the clinician can readily select a treatment regimen that is compatible with the diagnosis, such as initiating renal replacement therapy, withdrawing delivery of compounds that are known to be damaging to the kidney, kidney transplantation, delaying or avoiding procedures that are known to be damaging to the kidney, modifying diuretic administration, initiating goal directed therapy, etc. The skilled artisan is aware of appropriate treatments for numerous diseases discussed in relation to the methods of diagnosis described herein. See, e.g., Merck Manual of Diagnosis and Therapy, 17th Ed. Merck Research Laboratories, Whitehouse Station, N J, 1999. In addition, since the methods and compositions described herein provide prognostic information, the markers of the present invention may be used to monitor a course of treatment. For example, improved or worsened prognostic state may indicate that a particular treatment is or is not efficacious.

One skilled in the art readily appreciates that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The examples provided herein are representative of preferred embodiments, are exemplary, and are not intended as limitations on the scope of the invention.

EXAMPLE 1 Contrast-Induced Nephropathy Sample Collection

The objective of this sample collection study is to collect samples of plasma and urine and clinical data from patients before and after receiving intravascular contrast media. Approximately 250 adults undergoing radiographic/angiographic procedures involving intravascular administration of iodinated contrast media are enrolled. To be enrolled in the study, each patient must meet all of the following inclusion criteria and none of the following exclusion criteria:

Inclusion Criteria

males and females 18 years of age or older;

undergoing a radiographic/angiographic procedure (such as a CT scan or coronary intervention) involving the intravascular administration of contrast media;

expected to be hospitalized for at least 48 hours after contrast administration.

able and willing to provide written informed consent for study participation and to comply with all study procedures.

Exclusion Criteria

renal transplant recipients;

acutely worsening renal function prior to the contrast procedure;

already receiving dialysis (either acute or chronic) or in imminent need of dialysis at enrollment;

expected to undergo a major surgical procedure (such as involving cardiopulmonary bypass) or an additional imaging procedure with contrast media with significant risk for further renal insult within the 48 hrs following contrast administration;

participation in an interventional clinical study with an experimental therapy within the previous 30 days;

known infection with human immunodeficiency virus (HIV) or a hepatitis virus.

Immediately prior to the first contrast administration (and after any pre-procedure hydration), an EDTA anti-coagulated blood sample (10 mL) and a urine sample (10 mL) are collected from each patient. Blood and urine samples are then collected at 4 (±0.5), 8 (±1), 24 (±2) 48 (±2), and 72 (±2) hrs following the last administration of contrast media during the index contrast procedure. Blood is collected via direct venipuncture or via other available venous access, such as an existing femoral sheath, central venous line, peripheral intravenous line or hep-lock. These study blood samples are processed to plasma at the clinical site, frozen and shipped to Astute Medical, Inc., San Diego, Calif. The study urine samples are frozen and shipped to Astute Medical, Inc.

Serum creatinine is assessed at the site immediately prior to the first contrast administration (after any pre-procedure hydration) and at 4 (±0.5), 8 (±1), 24 (±2) and 48 (±2)), and 72 (±2) hours following the last administration of contrast (ideally at the same time as the study samples are obtained). In addition, each patient's status is evaluated through day 30 with regard to additional serum and urine creatinine measurements, a need for dialysis, hospitalization status, and adverse clinical outcomes (including mortality).

Prior to contrast administration, each patient is assigned a risk based on the following assessment: systolic blood pressure <80 mm Hg=5 points; intra-arterial balloon pump=5 points; congestive heart failure (Class III-IV or history of pulmonary edema)=5 points; age >75 yrs=4 points; hematocrit level <39% for men, <35% for women=3 points; diabetes=3 points; contrast media volume=1 point for each 100 mL; serum creatinine level >1.5 g/dL=4 points OR estimated GFR 40-60 mL/min/1.73 m²=2 points, 20-40 mL/min/1.73 m²=4 points, <20 mL/min/1.73 m²=6 points. The risks assigned are as follows: risk for CIN and dialysis: 5 or less total points=risk of CIN—7.5%, risk of dialysis—0.04%; 6-10 total points=risk of CIN—14%, risk of dialysis—0.12%; 11-16 total points=risk of CIN—26.1%, risk of dialysis—1.09%; >16 total points=risk of CIN—57.3%, risk of dialysis—12.8%.

EXAMPLE 2 Cardiac Surgery Sample Collection

The objective of this sample collection study is to collect samples of plasma and urine and clinical data from patients before and after undergoing cardiovascular surgery, a procedure known to be potentially damaging to kidney function. Approximately 900 adults undergoing such surgery are enrolled. To be enrolled in the study, each patient must meet all of the following inclusion criteria and none of the following exclusion criteria:

Inclusion Criteria

males and females 18 years of age or older;

undergoing cardiovascular surgery;

Toronto/Ottawa Predictive Risk Index for Renal Replacement risk score of at least 2 (Wijeysundera et al., JAMA 297: 1801-9, 2007); and

able and willing to provide written informed consent for study participation and to comply with all study procedures.

Exclusion Criteria

known pregnancy;

previous renal transplantation;

acutely worsening renal function prior to enrollment (e.g., any category of RIFLE criteria);

already receiving dialysis (either acute or chronic) or in imminent need of dialysis at enrollment;

currently enrolled in another clinical study or expected to be enrolled in another clinical study within 7 days of cardiac surgery that involves drug infusion or a therapeutic intervention for AKI;

known infection with human immunodeficiency virus (HIV) or a hepatitis virus.

Within 3 hours prior to the first incision (and after any pre-procedure hydration), an EDTA anti-coagulated blood sample (10 mL), whole blood (3 mL), and a urine sample (35 mL) are collected from each patient. Blood and urine samples are then collected at 3 (±0.5), 6 (±0.5), 12 (±1), 24 (±2) and 48 (±2) hrs following the procedure and then daily on days 3 through 7 if the subject remains in the hospital. Blood is collected via direct venipuncture or via other available venous access, such as an existing femoral sheath, central venous line, peripheral intravenous line or hep-lock. These study blood samples are frozen and shipped to Astute Medical, Inc., San Diego, Calif. The study urine samples are frozen and shipped to Astute Medical, Inc.

EXAMPLE 3 Acutely Ill Subject Sample Collection

The objective of this study is to collect samples from acutely ill patients. Approximately 1900 adults expected to be in the ICU for at least 48 hours will be enrolled. To be enrolled in the study, each patient must meet all of the following inclusion criteria and none of the following exclusion criteria:

Inclusion Criteria

males and females 18 years of age or older;

Study population 1: approximately 300 patients that have at least one of:

shock (SBP<90 mmHg and/or need for vasopressor support to maintain MAP>60 mmHg and/or documented drop in SBP of at least 40 mmHg); and

sepsis;

Study population 2: approximately 300 patients that have at least one of:

IV antibiotics ordered in computerized physician order entry (CPOE) within 24 hours of enrollment;

contrast media exposure within 24 hours of enrollment;

increased Intra-Abdominal Pressure with acute decompensated heart failure; and

severe trauma as the primary reason for ICU admission and likely to be hospitalized in the ICU for 48 hours after enrollment;

Study population 3: approximately 300 patients expected to be hospitalized through acute care setting (ICU or ED) with a known risk factor for acute renal injury (e.g. sepsis, hypotension/shock (Shock=systolic BP<90 mmHg and/or the need for vasopressor support to maintain a MAP>60 mmHg and/or a documented drop in SBP>40 mmHg), major trauma, hemorrhage, or major surgery); and/or expected to be hospitalized to the ICU for at least 24 hours after enrollment; Study population 4: approximately 1000 patients that are 21 years of age or older, within 24 hours of being admitted into the ICU, expected to have an indwelling urinary catheter for at least 48 hours after enrollment, and have at least one of the following acute conditions within 24 hours prior to enrollment: (i) respiratory SOFA score of ≧2 (PaO2/FiO2<300), (ii) cardiovascular SOFA score of ≧1 (MAP<70 mm Hg and/or any vasopressor required). Exclusion Criteria known pregnancy; institutionalized individuals; previous renal transplantation; known acutely worsening renal function prior to enrollment (e.g., any category of RIFLE criteria); received dialysis (either acute or chronic) within 5 days prior to enrollment or in imminent need of dialysis at the time of enrollment; known infection with human immunodeficiency virus (HIV) or a hepatitis virus; meets any of the following: (i) active bleeding with an anticipated need for >4 units PRBC in a day; (ii) hemoglobin<7 g/dL; (iii) any other condition that in the physician's opinion would contraindicate drawing serial blood samples for clinical study purposes; meets only the SBP<90 mmHg inclusion criterion set forth above, and does not have shock in the attending physician's or principal investigator's opinion;

After obtaining informed consent, an EDTA anti-coagulated blood sample (10 mL) and a urine sample (25-50 mL) are collected from each patient. Blood and urine samples are then collected at 4 (±0.5) and 8 (±1) hours after contrast administration (if applicable); at 12 (±1), 24 (±2), 36 (±2), 48 (±2), 60 (±2), 72 (±2), and 84 (±2) hours after enrollment, and thereafter daily up to day 7 to day 14 while the subject is hospitalized. Blood is collected via direct venipuncture or via other available venous access, such as an existing femoral sheath, central venous line, peripheral intravenous line or hep-lock. These study blood samples are processed to plasma at the clinical site, frozen and shipped to Astute Medical, Inc., San Diego, Calif. The study urine samples are frozen and shipped to Astute Medical, Inc.

EXAMPLE 4 Immunoassay Format

Analytes are measured using standard sandwich enzyme immunoassay techniques. A first antibody which binds the analyte is immobilized in wells of a 96 well polystyrene microplate. Analyte standards and test samples are pipetted into the appropriate wells and any analyte present is bound by the immobilized antibody. After washing away any unbound substances, a horseradish peroxidase-conjugated second antibody which binds the analyte is added to the wells, thereby forming sandwich complexes with the analyte (if present) and the first antibody. Following a wash to remove any unbound antibody-enzyme reagent, a substrate solution comprising tetramethylbenzidine and hydrogen peroxide is added to the wells. Color develops in proportion to the amount of analyte present in the sample. The color development is stopped and the intensity of the color is measured at 540 nm or 570 nm. An analyte concentration is assigned to the test sample by comparison to a standard curve determined from the analyte standards.

Units for the concentrations reported in the following data tables are as follows: Heat shock 70 kDa protein 1—pg/mL, Alpha-1-antitrypsin Neutrophil elastase complex—pg/mL, Stromelysin-1:Metalloproteinase inhibitor 2 complex—pg/mL, Insulin-like growth factor 1 receptor—ng/mL, Myeloid differentiation primary response protein MyD88—ng/mL, Neuronal cell adhesion molecule—ng/mL, and Tumor necrosis factor ligand superfamily member 10—pg/mL. In the case of those kidney injury markers which are membrane proteins as described herein, the assays used in these examples detect soluble forms thereof.

EXAMPLE 5 Apparently Healthy Donor and Chronic Disease Patient Samples

Human urine samples from donors with no known chronic or acute disease (“Apparently Healthy Donors”) were purchased from two vendors (Golden West Biologicals, Inc., 27625 Commerce Center Dr., Temecula, Calif. 92590 and Virginia Medical Research, Inc., 915 First Colonial Rd., Virginia Beach, Va. 23454). The urine samples were shipped and stored frozen at less than −20° C. The vendors supplied demographic information for the individual donors including gender, race (Black/White), smoking status and age.

Human urine samples from donors with various chronic diseases (“Chronic Disease Patients”) including congestive heart failure, coronary artery disease, chronic kidney disease, chronic obstructive pulmonary disease, diabetes mellitus and hypertension were purchased from Virginia Medical Research, Inc., 915 First Colonial Rd., Virginia Beach, Va. 23454. The urine samples were shipped and stored frozen at less than −20 degrees centigrade. The vendor provided a case report form for each individual donor with age, gender, race (Black/White), smoking status and alcohol use, height, weight, chronic disease(s) diagnosis, current medications and previous surgeries.

EXAMPLE 6 Use of Kidney Injury Markers for Evaluating Renal Status in Patients

Patients from the intensive care unit (ICU) were enrolled in the following study. Each patient was classified by kidney status as non-injury (0), risk of injury (R), injury (I), and failure (F) according to the maximum stage reached within 7 days of enrollment as determined by the RIFLE criteria. EDTA anti-coagulated blood samples (10 mL) and a urine samples (25-30 mL) were collected from each patient at enrollment, 4 (±0.5) and 8 (±1) hours after contrast administration (if applicable); at 12 (±1), 24 (±2), and 48 (±2) hours after enrollment, and thereafter daily up to day 7 to day 14 while the subject is hospitalized. Markers were each measured by standard immunoassay methods using commercially available assay reagents in the urine samples and the plasma component of the blood samples collected.

Two cohorts were defined to represent a “diseased” and a “normal” population. While these terms are used for convenience, “diseased” and “normal” simply represent two cohorts for comparison (say RIFLE 0 vs RIFLE R, I and F; RIFLE 0 vs RIFLE R; RIFLE 0 and R vs RIFLE I and F; etc.). The time “prior max stage” represents the time at which a sample is collected, relative to the time a particular patient reaches the lowest disease stage as defined for that cohort, binned into three groups which are +/−12 hours. For example, “24 hr prior” which uses 0 vs R, I, F as the two cohorts would mean 24 hr (+/−12 hours) prior to reaching stage R (or I if no sample at R, or F if no sample at R or I).

A receiver operating characteristic (ROC) curve was generated for each biomarker measured and the area under each ROC curve (AUC) is determined. Patients in Cohort 2 were also separated according to the reason for adjudication to cohort 2 as being based on serum creatinine measurements (sCr), being based on urine output (UO), or being based on either serum creatinine measurements or urine output. Using the same example discussed above (0 vs R, I, F), for those patients adjudicated to stage R, I, or F on the basis of serum creatinine measurements alone, the stage 0 cohort may include patients adjudicated to stage R, I, or F on the basis of urine output; for those patients adjudicated to stage R, I, or F on the basis of urine output alone, the stage 0 cohort may include patients adjudicated to stage R, I, or F on the basis of serum creatinine measurements; and for those patients adjudicated to stage R, I, or F on the basis of serum creatinine measurements or urine output, the stage 0 cohort contains only patients in stage 0 for both serum creatinine measurements and urine output. Also, in the data for patients adjudicated on the basis of serum creatinine measurements or urine output, the adjudication method which yielded the most severe RIFLE stage is used.

The ability to distinguish cohort 1 from Cohort 2 was determined using ROC analysis. SE is the standard error of the AUC, n is the number of sample or individual patients (“pts,” as indicated). Standard errors are calculated as described in Hanley, J. A., and McNeil, B. J., The meaning and use of the area under a receiver operating characteristic (ROC) curve. Radiology (1982) 143: 29-36; p values are calculated with a two-tailed Z-test. An AUC<0.5 is indicative of a negative going marker for the comparison, and an AUC>0.5 is indicative of a positive going marker for the comparison.

Various threshold (or “cutoff”) concentrations were selected, and the associated sensitivity and specificity for distinguishing cohort 1 from cohort 2 are determined. OR is the odds ratio calculated for the particular cutoff concentration, and 95% CI is the confidence interval for the odds ratio.

TABLE 1 Comparison of marker levels in urine samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0) and in urine samples collected from subjects at 0, 24 hours, and 48 hours prior to reaching stage R, I or F in Cohort 2. Stromelysin-1: Metalloproteinase inhibitor 2 complex 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.487 0.237 0.487 0.487 0.487 0.362 Average 328 5.13 328 22.4 328 0.362 Stdev 1910 21.0 1910 65.2 1910 0.176 p(t-test) 0.47 0.49 0.81 Min 0.237 0.237 0.237 0.237 0.237 0.237 Max 13900 91.7 13900 267 13900 0.487 n (Samp) 53 19 53 19 53 2 n (Patient) 42 19 42 19 42 2 sCr only Median 0.487 0.487 0.487 0.487 0.487 0.487 Average 193 0.387 193 111 193 0.487 Stdev 1440 0.137 1440 235 1440 0 p(t-test) 0.77 0.90 0.85 Min 0.237 0.237 0.237 0.237 0.237 0.487 Max 13900 0.487 13900 530 13900 0.487 n (Samp) 93 5 93 5 93 2 n (Patient) 73 5 73 5 73 2 UO only Median 0.487 0.237 0.487 0.487 0.487 0.487 Average 348 6.40 348 117 348 0.425 Stdev 2070 23.6 2070 431 2070 0.125 p(t-test) 0.53 0.62 0.74 Min 0.237 0.237 0.237 0.237 0.237 0.237 Max 13900 91.7 13900 1930 13900 0.487 n (Samp) 45 15 45 20 45 4 n (Patient) 35 15 35 20 35 4 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.32 0.47 0.39 0.44 0.57 0.58 0.35 0.63 0.54 SE 0.075 0.14 0.087 0.078 0.14 0.079 0.22 0.21 0.15 p 0.015 0.80 0.20 0.46 0.60 0.33 0.50 0.55 0.82 nCohort 1 53 93 45 53 93 45 53 93 45 nCohort 2 19 5 15 19 5 20 2 2 4 Cutoff 1 0 0 0 0 0 0.237 0 0.237 0.237 Sens 1 100%  100%  100%  100%  100%  70% 100%  100%  75% Spec 1 0% 0% 0%  0%  0% 49% 0% 44% 49% Cutoff 2 0 0 0 0 0 0 0 0.237 0 Sens 2 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 2 0% 0% 0%  0%  0%  0% 0% 44%  0% Cutoff 3 0 0 0 0 0 0 0 0.237 0 Sens 3 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 3 0% 0% 0%  0%  0%  0% 0% 44%  0% Cutoff 4 0.487 0.487 0.487 0.487 0.487 0.487 0.487 0.487 0.487 Sens 4 5% 0% 7% 21% 40% 25% 0%  0%  0% Spec 4 77%  82%  78%  77% 82% 78% 77%  82% 78% Cutoff 5 85.2 0.487 3.84 85.2 0.487 3.84 85.2 0.487 3.84 Sens 5 5% 0% 7% 11% 40% 25% 0%  0%  0% Spec 5 81%  82%  80%  81% 82% 80% 81%  82% 80% Cutoff 6 201 154 201 201 154 201 201 154 201 Sens 6 0% 0% 0%  5% 20% 10% 0%  0%  0% Spec 6 91%  90%  93%  91% 90% 93% 91%  90% 93% OR Quart 2 1.0 >3.6 5.1 0.70 0.96 >27 >0 >2.1 0 p Value 1.0 <0.29 0.17 0.67 0.98 <0.0044 <na  <0.56 na 95% CI of 0.058 >0.35 0.50 0.13 0.057 >2.8 >na  >0.18 na OR Quart2 17 na 52 3.7 16 na na  na na OR Quart 3 34 >1.0 12 1.3 1.0 >7.3 >1.1 >0 3.7 p Value 0.0021 <0.98 0.030 0.70 1.0 <0.088 <0.96 <na 0.29 95% CI of 3.6 >0.062 1.3 0.30 0.059 >0.74 >0.061 >na 0.32 OR Quart3 320 na 120 6.1 17 na na  na 42 OR Quart 4 6.5 >1.1 3.5 2.2 2.0 >6.7 >1.2 >0 0 p Value 0.10 <0.95 0.30 0.28 0.58 <0.10 <0.92 <na na 95% CI of 0.68 >0.064 0.32 0.52 0.17 >0.69 >0.066 >na na OR Quart4 63 na 38 9.6 24 na na  na na Heat shock 70 kDa protein 1 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 277 424 277 499 277 225 Average 558 408 558 702 558 700 Stdev 1110 392 1110 906 1110 897 p(t-test) 0.58 0.62 0.83 Min 0.297 0.335 0.297 0.335 0.297 140 Max 7800 1680 7800 3860 7800 1730 n (Samp) 51 18 51 18 51 3 n (Patient) 41 18 41 18 41 3 sCr only Median 286 459 286 982 286 774 Average 535 863 535 861 535 774 Stdev 943 767 943 592 943 776 p(t-test) 0.45 0.45 0.72 Min 0.297 217 0.297 0.335 0.297 225 Max 7800 1710 7800 1600 7800 1320 n (Samp) 90 5 90 5 90 2 n (Patient) 71 5 71 5 71 2 UO only Median 224 424 224 435 224 1680 Average 553 339 553 1260 553 1170 Stdev 1190 258 1190 2690 1190 801 p(t-test) 0.51 0.15 0.27 Min 0.297 0.335 0.297 0.335 0.297 140 Max 7800 812 7800 11800 7800 1820 n (Samp) 45 14 45 19 45 5 n (Patient) 35 14 35 19 35 5 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.52 0.68 0.53 0.57 0.70 0.64 0.57 0.69 0.78 SE 0.080 0.14 0.090 0.080 0.13 0.079 0.18 0.21 0.13 p 0.85 0.17 0.77 0.37 0.13 0.079 0.70 0.36 0.025 nCohort 1 51 90 45 51 90 45 51 90 45 nCohort 2 18 5 14 18 5 19 3 2 5 Cutoff 1 210 245 99.4 151 627 180 117 224 401 Sens 1 72% 80% 71% 72% 80% 74% 100%  100%  80% Spec 1 39% 47% 36% 29% 73% 44% 29% 43% 67% Cutoff 2 60.6 245 47.5 117 627 135 117 224 401 Sens 2 83% 80% 86% 83% 80% 84% 100%  100%  80% Spec 2 20% 47% 24% 29% 73% 38% 29% 43% 67% Cutoff 3 20.7 210 23.5 0.297 0.297 99.4 117 224 135 Sens 3 94% 100%  93% 100%  100%  95% 100%  100%  100%  Spec 3 10% 41% 16%  2%  1% 36% 29% 43% 38% Cutoff 4 574 545 512 574 545 512 574 545 512 Sens 4 17% 40% 21% 44% 80% 42% 33% 50% 60% Spec 4 71% 70% 71% 71% 70% 71% 71% 70% 71% Cutoff 5 755 763 664 755 763 664 755 763 664 Sens 5 11% 40% 14% 33% 60% 32% 33% 50% 60% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 1020 1020 1320 1020 1020 1320 1020 1020 1320 Sens 6  6% 40%  0% 17% 40% 16% 33% 50% 60% Spec 6 90% 90% 91% 90% 90% 91% 90% 90% 91% OR Quart 2 1.0 >2.1 0.56 1.9 0 6.8 >2.2 >1.0 >1.0 p Value 1.0 <0.56 0.57 0.42 na 0.099 <0.55 <0.98 <1.0 95% CI of 0.20 >0.18 0.079 0.38 na 0.69 >0.17 >0.062 >0.056 OR Quart2 4.9 na 4.0 9.9 na 67 na na na OR Quart 3 2.3 >1.0 3.2 1.4 0.96 12 >0 >0 >1.1 p Value 0.28 <1.0 0.16 0.67 0.98 0.033 <na  <na  <0.95 95% CI of 0.52 >0.059 0.63 0.27 0.056 1.2 >na  >na  >0.061 OR Quart3 10.0 na 16 7.7 16 110 na na na OR Quart 4 0.65 >2.1 0.56 2.3 3.1 9.0 >1.0 >1.0 >3.6 p Value 0.61 <0.56 0.57 0.30 0.34 0.057 <1.0 <0.98 <0.30 95% CI of 0.12 >0.18 0.079 0.48 0.30 0.94 >0.056 >0.062 >0.32 OR Quart4 3.5 na 4.0 11 33 87 na na na Insulin-like growth factor 1 receptor 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.0103 0.0103 0.0103 0.0169 nd nd Average 0.0275 0.0137 0.0275 0.0405 nd nd Stdev 0.0922 0.0113 0.0922 0.0818 nd nd p(t-test) 0.54 0.59 nd nd Min 0.000123 0.000172 0.000123 0.000172 nd nd Max 0.679 0.0423 0.679 0.365 nd nd n (Samp) 54 17 54 19 nd nd n (Patient) 43 17 43 19 nd nd sCr only Median 0.0103 0.00132 0.0103 0.0381 0.0103 0.0292 Average 0.0278 0.00733 0.0278 0.0354 0.0278 0.0292 Stdev 0.0804 0.00927 0.0804 0.0263 0.0804 0 p(t-test) 0.57 0.83 0.98 Min 0.000123 0.000172 0.000123 0.000519 0.000123 0.0292 Max 0.679 0.0197 0.679 0.0680 0.679 0.0292 n (Samp) 91 5 91 5 91 2 n (Patient) 73 5 73 5 73 2 UO only Median 0.0103 0.0169 0.0103 0.0115 0.0103 0.0150 Average 0.0292 0.0166 0.0292 0.0335 0.0292 0.0200 Stdev 0.0988 0.0108 0.0988 0.0799 0.0988 0.0216 p(t-test) 0.65 0.86 0.87 Min 0.000123 0.000519 0.000123 0.000172 0.000123 0.00132 Max 0.679 0.0423 0.679 0.365 0.679 0.0436 n (Samp) 47 13 47 20 47 3 n (Patient) 37 13 37 20 37 3 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.50 0.34 0.59 0.59 0.72 0.56 nd 0.81 0.63 SE 0.081 0.14 0.092 0.078 0.13 0.078 nd 0.19 0.18 p 0.98 0.25 0.33 0.23 0.10 0.47 nd 0.093 0.48 nCohort 1 54 91 47 54 91 47 nd 91 47 nCohort 2 17 5 13 19 5 20 nd 2 3 Cutoff 1 0.00573 0.000172 0.00454 0.00132 0.0169 0.00454 nd 0.0254 0.000519 Sens 1 76% 80% 92% 74% 80% 70% nd 100%  100%  Spec 1 30% 11% 36% 26% 67% 36% nd 79% 30% Cutoff 2 0.000519 0.000172 0.00454 0.000172 0.0169 0.000519 nd 0.0254 0.000519 Sens 2 82% 80% 92% 89% 80% 85% nd 100%  100%  Spec 2 20% 11% 36% 13% 67% 30% nd 79% 30% Cutoff 3 0.000172 0.000123 0.00454 0.000123 0.000172 0.000172 nd 0.0254 0.000519 Sens 3 94% 100%  92% 100%  100%  90% nd 100%  100%  Spec 3 13%  2% 36%  4% 11% 19% nd 79% 30% Cutoff 4 0.0169 0.0197 0.0169 0.0169 0.0197 0.0169 nd 0.0197 0.0169 Sens 4 35%  0% 46% 47% 60% 35% nd 100%  33% Spec 4 72% 71% 70% 72% 71% 70% nd 71% 70% Cutoff 5 0.0292 0.0292 0.0292 0.0292 0.0292 0.0292 nd 0.0292 0.0292 Sens 5  6%  0%  8% 32% 60% 15% nd  0% 33% Spec 5 85% 84% 85% 85% 84% 85% nd 84% 85% Cutoff 6 0.0388 0.0423 0.0388 0.0388 0.0423 0.0388 nd 0.0423 0.0388 Sens 6  6%  0%  8% 21% 40% 10% nd  0% 33% Spec 6 93% 92% 91% 93% 92% 91% nd 92% 91% OR Quart 2 1.2 >2.2 7.0 1.0 0 3.8 nd >0 >1.0 p Value 0.77 <0.54 0.097 1.0 na 0.14 nd <na <1.0 95% CI of 0.27 >0.18 0.71 0.21 na 0.64 nd >na >0.056 OR Quart2 5.7 na 69 4.8 na 23 nd  na na OR Quart 3 0.93 >0 3.5 1.0 1.0 3.8 nd >0 >1.1 p Value 0.93 <na  0.30 1.0 1.0 0.14 nd <na <0.95 95% CI of 0.19 >na  0.32 0.21 0.059 0.64 nd >na >0.061 OR Quart3 4.5 na 38 4.8 17 23 nd  na na OR Quart 4 0.93 >3.4 5.1 2.0 3.3 3.8 nd >2.1 >1.0 p Value 0.93 <0.30 0.17 0.33 0.32 0.14 nd <0.56 <1.0 95% CI of 0.19 >0.33 0.50 0.48 0.32 0.64 nd >0.18 >0.056 OR Quart4 4.5 na 52 8.7 34 23 nd  na na Interstitial collagenase: Metalloproteinase inhibitor 2 complex 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.233 0.233 0.233 0.233 0.233 0.231 Average 315 0.967 315 18.9 315 0.231 Stdev 2200 3.21 2200 68.2 2200 0.00389 p(t-test) 0.54 0.56 0.84 Min 0.228 0.228 0.228 0.228 0.228 0.228 Max 16000 14.2 16000 297 16000 0.233 n (Samp) 53 19 53 19 53 2 n (Patient) 42 19 42 19 42 2 sCr only Median 0.233 0.233 0.233 0.233 0.233 0.228 Average 184 4.37 184 6.08 184 0.228 Stdev 1660 6.22 1660 13.1 1660 0 p(t-test) 0.81 0.81 0.88 Min 0.228 0.228 0.228 0.228 0.228 0.228 Max 16000 14.2 16000 29.5 16000 0.228 n (Samp) 93 5 93 5 93 2 n (Patient) 73 5 73 5 73 2 UO only Median 0.233 0.233 0.233 0.233 0.233 0.231 Average 360 0.232 360 37.2 360 3.72 Stdev 2380 0.00268 2380 105 2380 6.99 p(t-test) 0.56 0.55 0.77 Min 0.228 0.228 0.228 0.228 0.228 0.228 Max 16000 0.233 16000 384 16000 14.2 n (Samp) 45 15 45 20 45 4 n (Patient) 35 15 35 20 35 4 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.50 0.61 0.40 0.58 0.56 0.50 0.42 0.18 0.42 SE 0.078 0.14 0.087 0.078 0.14 0.078 0.22 0.18 0.16 p 0.96 0.41 0.25 0.33 0.65 0.98 0.71 0.086 0.63 nCohort 1 53 93 45 53 93 45 53 93 45 nCohort 2 19 5 15 19 5 20 2 2 4 Cutoff 1 0 0.228 0 0.228 0.228 0 0 0 0 Sens 1 100%  80% 100%  74% 80% 100%  100%  100%  100%  Spec 1 0% 37% 0% 45% 37%  0% 0% 0%  0% Cutoff 2 0 0.228 0 0 0.228 0 0 0 0 Sens 2 100%  80% 100%  100%  80% 100%  100%  100%  100%  Spec 2 0% 37% 0%  0% 37%  0% 0% 0%  0% Cutoff 3 0 0 0 0 0 0 0 0 0 Sens 3 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 3 0%  0% 0%  0%  0%  0% 0% 0%  0% Cutoff 4 0.233 0.233 0.233 0.233 0.233 0.233 0.233 0.233 0.233 Sens 4 5% 40% 0% 26% 20% 30% 0% 0% 25% Spec 4 77%  78% 73%  77% 78% 73% 77%  78%  73% Cutoff 5 2.99 2.13 2.99 2.99 2.13 2.99 2.99 2.13 2.99 Sens 5 5% 40% 0% 21% 20% 25% 0% 0% 25% Spec 5 81%  81% 80%  81% 81% 80% 81%  81%  80% Cutoff 6 30.3 18.5 18.5 30.3 18.5 18.5 30.3 18.5 18.5 Sens 6 0%  0% 0% 11% 20% 15% 0% 0%  0% Spec 6 91%  90% 93%  91% 90% 93% 91%  90%  93% OR Quart 2 0.12 >1.0 >10 0 >1.0 0.43 >1.1 >0 1.1 p Value 0.061 <1.0 <0.047 na <1.0 0.27 <0.96 <na 0.95 95% CI of 0.012 >0.059 >1.0 na >0.059 0.095 >0.061 >na 0.061 OR Quart2 1.1 na na na na 1.9 na  na 20 OR Quart 3 3.1 >2.2 >5.5 2.6 >3.4 0.30 >0 >0 0 p Value 0.100 <0.54 <0.15 0.18 <0.30 0.14 <na  <na na 95% CI of 0.80 >0.18 >0.53 0.65 >0.33 0.060 >na  >na na OR Quart3 12 na na 10 na 1.5 na  na na OR Quart 4 0.12 >2.1 >7.5 1.0 >1.0 0.70 >1.2 >2.3 2.4 p Value 0.061 <0.56 <0.085 1.0 <1.0 0.62 <0.92 <0.51 0.50 95% CI of 0.012 >0.18 >0.76 0.23 >0.059 0.17 >0.066 >0.19 0.19 OR Quart4 1.1 na na 4.3 na 2.8 na  na 31 72 kDa type IV collagenase: Metalloproteinase inhibitor 2 complex 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 63.6 11.3 63.6 82.5 nd nd Average 610 807 610 1160 nd nd Stdev 2290 2050 2290 3840 nd nd p(t-test) 0.74 0.48 nd nd Min 1.15 1.15 1.15 1.15 nd nd Max 16000 8520 16000 16000 nd nd n (Samp) 50 19 50 17 nd nd n (Patient) 40 19 40 17 nd nd sCr only Median 34.8 29.2 34.8 292 34.8 918 Average 736 628 736 509 736 918 Stdev 2550 1220 2550 670 2550 1230 p(t-test) 0.92 0.86 0.92 Min 1.15 1.19 1.15 1.19 1.15 51.6 Max 16000 3060 16000 1450 16000 1780 n (Samp) 88 6 88 4 88 2 n (Patient) 72 6 72 4 72 2 UO only Median 21.1 1.19 21.1 158 21.1 3060 Average 607 816 607 1240 607 4730 Stdev 2400 2210 2400 3680 2400 5730 p(t-test) 0.77 0.41 0.012 Min 1.15 1.15 1.15 1.15 1.15 30.3 Max 16000 8520 16000 16000 16000 11100 n (Samp) 45 15 45 19 45 3 n (Patient) 35 15 35 19 35 3 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.52 0.59 0.53 0.54 0.64 0.55 nd 0.72 0.82 SE 0.079 0.13 0.087 0.082 0.15 0.080 nd 0.21 0.15 p 0.85 0.49 0.73 0.62 0.37 0.51 nd 0.30 0.033 nCohort 1 50 88 45 50 88 45 nd 88 45 nCohort 2 19 6 15 17 4 19 nd 2 3 Cutoff 1 1.15 1.19 1.15 1.15 36.4 1.15 nd 36.4 21.1 Sens 1 95% 83% 93% 88% 75% 79% nd 100%  100%  Spec 1 24% 45% 20% 24% 51% 20% nd 51% 51% Cutoff 2 1.15 1.19 1.15 1.15 1.15 0 nd 36.4 21.1 Sens 2 95% 83% 93% 88% 100%  100%  nd 100%  100%  Spec 2 24% 45% 20% 24% 18%  0% nd 51% 51% Cutoff 3 1.15 1.15 1.15 0 1.15 0 nd 36.4 21.1 Sens 3 95% 100%  93% 100%  100%  100%  nd 100%  100%  Spec 3 24% 18% 20%  0% 18%  0% nd 51% 51% Cutoff 4 189 295 189 189 295 189 nd 295 189 Sens 4 32% 33% 33% 41% 50% 42% nd 50% 67% Spec 4 70% 70% 71% 70% 70% 71% nd 70% 71% Cutoff 5 462 579 419 462 579 419 nd 579 419 Sens 5 21% 33% 20% 18% 25% 26% nd 50% 67% Spec 5 80% 81% 80% 80% 81% 80% nd 81% 80% Cutoff 6 1190 1230 1190 1190 1230 1190 nd 1230 1190 Sens 6 16% 17% 13% 12% 25% 16% nd 50% 67% Spec 6 90% 91% 91% 90% 91% 91% nd 91% 91% OR Quart 2 4.1 >4.6 12 1.8 >1.0 1.0 nd >0 >1.1 p Value 0.076 <0.19 0.030 0.48 <0.98 1.0 nd <na  <0.95 95% CI of 0.86 >0.47 1.3 0.35 >0.062 0.20 nd >na  >0.061 OR Quart2 20 na 120 9.2 na 5.0 nd na na OR Quart 3 1.0 >0 3.5 1.8 >1.0 1.8 nd >1.0 >0 p Value 1.0 <na  0.30 0.48 <0.98 0.45 nd <0.97 <na  95% CI of 0.17 >na  0.32 0.35 >0.062 0.39 nd >0.061 >na  OR Quart3 5.8 na 38 9.2 na 8.2 nd na na OR Quart 4 1.8 >2.1 5.1 1.3 >2.2 1.4 nd >1.0 >2.4 p Value 0.48 <0.56 0.17 0.74 <0.53 0.69 nd <1.0 <0.50 95% CI of 0.36 >0.18 0.50 0.25 >0.18 0.29 nd >0.059 >0.19 OR Quart4 9.1 na 52 7.2 na 6.4 nd na na Neural cell adhesion molecule 1 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 2300 3540 2300 2640 2300 2890 Average 2930 3880 2930 4210 2930 3140 Stdev 2240 4050 2240 6650 2240 1810 p(t-test) 7.5E−4 6.1E−4 0.55 Min 6.83 221 6.83 216 6.83 293 Max 22000 40700 22000 55700 22000 6560 n (Samp) 460 117 460 125 460 45 n (Patient) 223 117 223 125 223 45 sCr only Median 2840 2320 2840 2390 2840 1990 Average 3480 2560 3480 3160 3480 2390 Stdev 3360 1650 3360 2380 3360 1630 p(t-test) 0.087 0.52 0.11 Min 6.83 221 6.83 216 6.83 387 Max 55700 6210 55700 10800 55700 6110 n (Samp) 1008 39 1008 45 1008 25 n (Patient) 374 39 374 45 374 25 UO only Median 2410 3860 2410 3060 2410 2880 Average 3010 4670 3010 4630 3010 3260 Stdev 2070 4820 2070 7120 2070 1990 p(t-test) 9.0E−8 4.0E−5 0.44 Min 173 506 173 224 173 293 Max 11700 40700 11700 55700 11700 9700 n (Samp) 432 107 432 116 432 43 n (Patient) 172 107 172 116 172 43 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.61 0.40 0.66 0.56 0.46 0.58 0.56 0.37 0.56 SE 0.030 0.049 0.031 0.030 0.045 0.031 0.046 0.061 0.047 p 3.7E−4 0.044 6.1E−7 0.042 0.42 0.014 0.19 0.031 0.22 nCohort 1 460 1008 432 460 1008 432 460 1008 432 nCohort 2 117 39 107 125 45 116 45 25 43 Cutoff 1 2270 1090 2690 1950 1680 2040 2150 1190 2250 Sens 1 70% 72% 70% 70% 71% 71% 71% 72% 72% Spec 1 50% 12% 55% 41% 25% 40% 47% 14% 45% Cutoff 2 1550 994 2000 1250 1110 1560 1500 1110 1650 Sens 2 80% 82% 80% 80% 80% 80% 80% 80% 81% Spec 2 30% 10% 39% 20% 13% 29% 28% 13% 31% Cutoff 3 994 615 1450 898 883 986 485 491 881 Sens 3 91% 92% 91% 90% 91% 91% 91% 92% 91% Spec 3 13%  4% 26% 10%  8% 12%  3%  2%  9% Cutoff 4 3540 4070 3650 3540 4070 3650 3540 4070 3650 Sens 4 50% 18% 54% 37% 31% 39% 38% 16% 35% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 4180 4960 4430 4180 4960 4430 4180 4960 4430 Sens 5 31%  8% 33% 30% 20% 31% 31%  8% 26% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 5630 6470 6000 5630 6470 6000 5630 6470 6000 Sens 6 17%  0% 23% 20%  9% 20%  9%  0%  9% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 1.1 1.5 1.3 0.87 0.72 1.3 0.65 1.0 1.1 p Value 0.87 0.43 0.47 0.65 0.49 0.35 0.43 1.00 0.80 95% CI of 0.55 0.53 0.63 0.49 0.29 0.72 0.22 0.25 0.40 OR Quart2 2.1 4.3 2.8 1.6 1.8 2.5 1.9 4.1 3.3 OR Quart 3 1.8 1.5 2.9 0.87 1.2 1.3 1.9 1.8 2.3 p Value 0.050 0.43 0.0021 0.65 0.67 0.43 0.15 0.36 0.083 95% CI of 1.00 0.53 1.5 0.49 0.53 0.69 0.80 0.51 0.90 OR Quart3 3.4 4.3 5.7 1.6 2.7 2.4 4.5 6.1 5.8 OR Quart 4 2.6 2.6 3.7 1.7 1.2 2.1 1.6 2.6 1.9 p Value 0.0015 0.052 9.9E−5 0.048 0.67 0.015 0.29 0.11 0.17 95% CI of 1.4 0.99 1.9 1.0 0.53 1.2 0.67 0.80 0.75 OR Quart4 4.7 6.8 7.3 3.0 2.7 3.7 3.9 8.3 5.1 Tumor necrosis factor ligand superfamily member 10 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.0285 0.0335 0.0285 0.0324 0.0285 0.0287 Average 2.78 1.92 2.78 2.63 2.78 1.54 Stdev 9.69 7.52 9.69 13.7 9.69 6.36 p(t-test) 0.37 0.89 0.39 Min 0.0110 0.0110 0.0110 0.0110 0.0110 0.0110 Max 92.3 63.9 92.3 134 92.3 41.7 n (Samp) 449 115 449 124 449 47 n (Patient) 222 115 222 124 222 47 sCr only Median 0.0285 0.0257 0.0285 0.0317 0.0285 0.0287 Average 2.84 0.930 2.84 1.03 2.84 2.16 Stdev 11.0 3.19 11.0 3.99 11.0 8.53 p(t-test) 0.30 0.27 0.76 Min 0.0110 0.0139 0.0110 0.0139 0.0110 0.0110 Max 159 13.9 159 24.4 159 41.7 n (Samp) 997 36 997 45 997 24 n (Patient) 379 36 379 45 379 24 UO only Median 0.0287 0.0335 0.0287 0.0312 0.0287 0.0287 Average 3.05 3.56 3.05 3.58 3.05 0.744 Stdev 10.6 13.1 10.6 17.5 10.6 2.23 p(t-test) 0.67 0.68 0.15 Min 0.0110 0.0110 0.0110 0.0110 0.0110 0.0139 Max 92.3 79.6 92.3 134 92.3 12.3 n (Samp) 419 107 419 115 419 44 n (Patient) 175 107 175 115 175 44 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.52 0.42 0.50 0.52 0.52 0.50 0.49 0.50 0.46 SE 0.030 0.051 0.031 0.030 0.044 0.030 0.045 0.060 0.047 p 0.58 0.11 0.97 0.49 0.68 0.99 0.80 0.99 0.45 nCohort 1 449 997 419 449 997 419 449 997 419 nCohort 2 115 36 107 124 45 115 47 24 44 Cutoff 1 0.0239 0.0217 0.0247 0.0237 0.0247 0.0239 0.0217 0.0239 0.0227 Sens 1 70% 72% 71% 73% 71% 70% 74% 71% 70% Spec 1 38% 22% 40% 35% 41% 34% 27% 37% 26% Cutoff 2 0.0205 0.0162 0.0159 0.0217 0.0217 0.0227 0.0205 0.0205 0.0205 Sens 2 80% 83% 86% 82% 82% 81% 83% 88% 84% Spec 2 22% 15% 16% 27% 22% 26% 22% 18% 19% Cutoff 3 0.0139 0.0110 0.0139 0.0147 0.0147 0.0147 0.0110 0.0139 0.0147 Sens 3 93% 100%  92% 91% 91% 90% 98% 92% 91% Spec 3  8%  4%  7% 14% 11% 12%  4%  7% 12% Cutoff 4 0.0526 0.0439 0.0526 0.0526 0.0439 0.0526 0.0526 0.0439 0.0526 Sens 4 16% 17% 17% 19% 18% 20% 19% 21% 18% Spec 4 73% 73% 72% 73% 73% 72% 73% 73% 72% Cutoff 5 1.17 0.327 1.42 1.17 0.327 1.42 1.17 0.327 1.42 Sens 5 14% 11% 15% 14% 13% 16% 13% 17% 11% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 6.80 6.49 8.01 6.80 6.49 8.01 6.80 6.49 8.01 Sens 6  9%  6%  7%  6%  4%  5%  4%  4%  2% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 1.0 1.3 2.7 1.7 0.62 1.8 2.3 0.66 2.5 p Value 1.0 0.58 0.0019 0.076 0.34 0.053 0.063 0.53 0.054 95% CI of 0.54 0.46 1.4 0.95 0.24 0.99 0.96 0.18 0.98 OR Quart2 1.8 3.9 5.0 3.1 1.6 3.2 5.6 2.4 6.3 OR Quart 3 2.3 1.5 1.4 2.7 1.9 1.6 1.6 1.5 1.6 p Value 0.0030 0.43 0.31 7.0E−4 0.10 0.10 0.35 0.43 0.33 95% CI of 1.3 0.53 0.72 1.5 0.89 0.91 0.61 0.53 0.61 OR Quart3 4.0 4.3 2.7 4.8 4.0 3.0 3.9 4.3 4.4 OR Quart 4 0.68 2.2 1.6 0.94 0.62 0.96 1.3 0.83 1.5 p Value 0.25 0.11 0.18 0.85 0.34 0.89 0.63 0.76 0.44 95% CI of 0.35 0.84 0.81 0.49 0.24 0.50 0.48 0.25 0.54 OR Quart4 1.3 6.0 3.0 1.8 1.6 1.8 3.3 2.7 4.0 Myeloid differentiation primary response protein MyD88 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.000533 0.000171 0.000533 0.000533 0.000533 0.000165 Average 0.0182 0.0146 0.0182 0.0138 0.0182 0.000900 Stdev 0.0708 0.0619 0.0708 0.0330 0.0708 0.00127 p(t-test) 0.79 0.73 0.68 Min 0.000126 0.000126 0.000126 0.000126 0.000126 0.000165 Max 0.671 0.371 0.671 0.171 0.671 0.00237 n (Samp) 98 36 98 33 98 3 n (Patient) 64 36 64 33 64 3 sCr only Median 0.000533 0.000171 0.000533 0.000165 0.000533 0.000165 Average 0.0184 0.00598 0.0184 0.00792 0.0184 0.00225 Stdev 0.0636 0.0133 0.0636 0.0140 0.0636 0.00419 p(t-test) 0.52 0.59 0.61 Min 0.000126 0.000126 0.000126 0.000126 0.000126 0.000126 Max 0.671 0.0400 0.671 0.0359 0.671 0.00853 n (Samp) 192 11 192 11 192 4 n (Patient) 114 11 114 11 114 4 UO only Median 0.000533 0.000352 0.000533 0.000533 0.000533 0.000533 Average 0.0113 0.0169 0.0113 0.0134 0.0113 0.00485 Stdev 0.0229 0.0676 0.0229 0.0332 0.0229 0.0101 p(t-test) 0.48 0.68 0.50 Min 0.000126 0.000126 0.000126 0.000126 0.000126 0.000165 Max 0.106 0.371 0.106 0.171 0.106 0.0253 n (Samp) 99 30 99 34 99 6 n (Patient) 61 30 61 34 61 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.42 0.42 0.45 0.55 0.41 0.55 0.39 0.31 0.51 SE 0.057 0.092 0.061 0.059 0.093 0.058 0.18 0.15 0.12 p 0.17 0.41 0.39 0.37 0.31 0.37 0.54 0.21 0.92 nCohort 1 98 192 99 98 192 99 98 192 99 nCohort 2 36 11 30 33 11 34 3 4 6 Cutoff 1 0.000126 0.000126 0.000126 0.000171 0.000126 0.000171 0.000126 0.000126 0.000126 Sens 1 86% 91% 87% 73% 73% 74% 100%  75% 100%  Spec 1  8% 11%  9% 40% 11% 42% 8% 11%  9% Cutoff 2 0.000126 0.000126 0.000126 0.000126 0 0.000126 0.000126 0 0.000126 Sens 2 86% 91% 87% 94% 100%  94% 100%  100%  100%  Spec 2  8% 11%  9%  8%  0%  9% 8%  0%  9% Cutoff 3 0 0.000126 0 0.000126 0 0.000126 0.000126 0 0.000126 Sens 3 100%  91% 100%  94% 100%  94% 100%  100%  100%  Spec 3  0% 11%  0%  8%  0%  9% 8%  0%  9% Cutoff 4 0.000533 0.00237 0.00309 0.000533 0.00237 0.00309 0.000533 0.00237 0.00309 Sens 4 22% 18% 27% 33% 27% 26% 33%  25% 17% Spec 4 71% 70% 71% 71% 70% 71% 71%  70% 71% Cutoff 5 0.0212 0.0190 0.0212 0.0212 0.0190 0.0212 0.0212 0.0190 0.0212 Sens 5 14% 18% 13% 18% 18% 18% 0%  0% 17% Spec 5 81% 80% 81% 81% 80% 81% 81%  80% 81% Cutoff 6 0.0484 0.0394 0.0393 0.0484 0.0394 0.0393 0.0484 0.0394 0.0393 Sens 6  3%  9%  3%  6%  0% 12% 0%  0%  0% Spec 6 91% 90% 91% 91% 90% 91% 91%  90% 91% OR Quart 2 0.12 0 1.3 3.0 0 3.2 >1.1 >1.0 1.0 p Value 0.055 na 0.71 0.048 na 0.055 <0.96 <0.99 1.0 95% CI of 0.014 na 0.37 1.0 na 0.98 >0.064 >0.062 0.13 OR Quart2 1.0 na 4.3 8.8 na 10 na na 7.7 OR Quart 3 3.4 3.9 0.64 0.23 1.4 2.1 >2.3 >2.1 0.48 p Value 0.024 0.10 0.53 0.083 0.70 0.23 <0.52 <0.55 0.56 95% CI of 1.2 0.77 0.16 0.044 0.29 0.62 >0.19 >0.18 0.041 OR Quart3 10.0 20 2.5 1.2 6.4 7.1 na na 5.6 OR Quart 4 2.2 1.0 3.1 1.3 1.4 1.7 >0 >1.0 0.46 p Value 0.16 0.98 0.051 0.61 0.68 0.39 <na  <0.99 0.54 95% CI of 0.74 0.14 0.99 0.43 0.30 0.50 >na  >0.062 0.039 OR Quart4 6.6 7.5 9.5 4.2 6.6 5.9 na na 5.4

TABLE 2 Comparison of marker levels in urine samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0 or R) and in urine samples collected from subjects at 0, 24 hours, and 48 hours prior to reaching stage I or F in Cohort 2. Stromelysin-1:Metalloproteinase inhibitor 2 complex 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.487 0.487 nd nd Average 202 23.1 nd nd Stdev 1420 69.4 nd nd p (t-test) 0.63 nd nd Min 0.237 0.237 nd nd Max 13900 267 nd nd n (Samp) 97 15 nd nd n (Patient) 74 15 nd nd sCr only Median 0.487 10.9 nd nd Average 181 181 nd nd Stdev 1340 303 nd nd p (t-test) 1.00 nd nd Min 0.237 0.487 nd nd Max 13900 530 nd nd n (Samp) 110 3 nd nd n (Patient) 85 3 nd nd UO only Median 0.237 0.487 0.237 5.71 Average 217 24.0 217 5.71 Stdev 1550 72.0 1550 7.39 p (t-test) 0.64 0.85 Min 0.237 0.237 0.237 0.487 Max 13900 267 13900 10.9 n (Samp) 82 14 82 2 n (Patient) 62 14 62 2 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.63 0.80 0.63 nd nd 0.77 SE 0.082 0.15 0.085 nd nd 0.20 p 0.12 0.048 0.12 nd nd 0.18 nCohort 1 97 110 82 nd nd 82 nCohort 2 15 3 14 nd nd 2 Cutoff 1 0.237 0.237 0.237 nd nd 0.237 Sens 1 87% 100%  79% nd nd 100%  Spec 1 45% 44% 55% nd nd 55% Cutoff 2 0.237 0.237 0 nd nd 0.237 Sens 2 87% 100%  100%  nd nd 100%  Spec 2 45% 44%  0% nd nd 55% Cutoff 3 0 0.237 0 nd nd 0.237 Sens 3 100%  100%  100%  nd nd 100%  Spec 3  0% 44%  0% nd nd 55% Cutoff 4 0.487 0.487 0.487 nd nd 0.487 Sens 4 20% 67% 14% nd nd 50% Spec 4 81% 82% 83% nd nd 83% Cutoff 5 0.487 0.487 0.487 nd nd 0.487 Sens 5 20% 67% 14% nd nd 50% Spec 5 81% 82% 83% nd nd 83% Cutoff 6 154 123 118 nd nd 118 Sens 6  7% 33%  7% nd nd  0% Spec 6 91% 90% 90% nd nd 90% OR Quart 2 >21 >1.0 2.1 nd nd >0 p Value <0.0051 <0.98 0.56 nd nd <na 95% CI of >2.5 >0.062 0.18 nd nd >na OR Quart 2 na na 25 nd nd na OR Quart 3 >0 >0 14 nd nd >1.0 p Value <na <na 0.018 nd nd <0.97 95% CI of >na >na 1.6 nd nd >0.061 OR Quart 3 na na 120 nd nd na OR Quart 4 >3.4 >2.1 2.1 nd nd >1.0 p Value <0.31 <0.56 0.56 nd nd <0.97 95% CI of >0.33 >0.18 0.18 nd nd >0.061 OR Quart 4 na na 25 nd nd na Heat shock 70 kDa protein 1 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 257 658 nd nd Average 500 1700 nd nd Stdev 872 3070 nd nd p (t-test) 0.0023 nd nd Min 0.297 0.335 nd nd Max 7800 11800 nd nd n (Samp) 95 14 nd nd n (Patient) 73 14 nd nd sCr only Median 283 1510 nd nd Average 534 1440 nd nd Stdev 897 318 nd nd p (t-test) 0.085 nd nd Min 0.297 1090 nd nd Max 7800 1710 nd nd n (Samp) 107 3 nd nd n (Patient) 83 3 nd nd UO only Median 225 435 225 1660 Average 503 1590 503 1660 Stdev 930 3220 930 215 p (t-test) 0.014 0.083 Min 0.297 0.335 0.297 1510 Max 7800 11800 7800 1820 n (Samp) 82 13 82 2 n (Patient) 62 13 62 2 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.70 0.93 0.62 nd nd 0.96 SE 0.082 0.10 0.088 nd nd 0.10 p 0.015 2.3E−5 0.17 nd nd 5.5E−6 nCohort 1 95 107 82 nd nd 82 nCohort 2 14 3 13 nd nd 2 Cutoff 1 401 1040 246 nd nd 1340 Sens 1 71% 100%  77% nd nd 100%  Spec 1 60% 91% 52% nd nd 94% Cutoff 2 246 1040 125 nd nd 1340 Sens 2 86% 100%  85% nd nd 100%  Spec 2 49% 91% 33% nd nd 94% Cutoff 3 125 1040 23.5 nd nd 1340 Sens 3 93% 100%  92% nd nd 100%  Spec 3 29% 91% 12% nd nd 94% Cutoff 4 529 545 512 nd nd 512 Sens 4 57% 100%  46% nd nd 100%  Spec 4 71% 70% 71% nd nd 71% Cutoff 5 755 770 755 nd nd 755 Sens 5 50% 100%  38% nd nd 100%  Spec 5 80% 80% 80% nd nd 80% Cutoff 6 1020 1040 1020 nd nd 1020 Sens 6 36% 100%  23% nd nd 100%  Spec 6 91% 91% 90% nd nd 90% OR Quart 2 2.1 >0 0.95 nd nd >0 p Value 0.56 <na 0.96 nd nd <na 95% CI of 0.18 >na 0.12 nd nd >na OR Quart 2 24 na 7.4 nd nd na OR Quart 3 4.5 >0 2.1 nd nd >0 p Value 0.19 <na 0.42 nd nd <na 95% CI of 0.47 >na 0.35 nd nd >na OR Quart 3 43 na 13 nd nd na OR Quart 4 8.7 >3.2 2.8 nd nd >2.2 p Value 0.051 <0.32 0.26 nd nd <0.53 95% CI of 0.99 >0.32 0.48 nd nd >0.19 OR Quart 4 76 na 16 nd nd na Insulin-like growth factor 1 receptor 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.0103 0.0170 0.0103 0.0197 nd nd Average 0.0238 0.0170 0.0238 0.0407 nd nd Stdev 0.0708 0.0233 0.0708 0.0903 nd nd p (t-test) 0.89 0.41 nd nd Min 0.000123 0.000519 0.000123 0.00132 nd nd Max 0.679 0.0335 0.679 0.365 nd nd n (Samp) 95 2 95 15 nd nd n (Patient) 74 2 74 15 nd nd sCr only Median nd nd 0.0103 0.0197 nd nd Average nd nd 0.0263 0.0160 nd nd Stdev nd nd 0.0743 0.00637 nd nd p (t-test) nd nd 0.81 nd nd Min nd nd 0.000123 0.00862 nd nd Max nd nd 0.679 0.0197 nd nd n (Samp) nd nd 108 3 nd nd n (Patient) nd nd 85 3 nd nd UO only Median nd nd 0.0103 0.0150 0.0103 0.0261 Average nd nd 0.0248 0.0422 0.0248 0.0261 Stdev nd nd 0.0761 0.0935 0.0761 0.0247 p (t-test) nd nd 0.45 0.98 Min nd nd 0.000123 0.00132 0.000123 0.00862 Max nd nd 0.679 0.365 0.679 0.0436 n (Samp) nd nd 82 14 82 2 n (Patient) nd nd 64 14 64 2 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.51 nd nd 0.62 0.57 0.62 nd nd 0.65 SE 0.21 nd nd 0.082 0.17 0.085 nd nd 0.21 p 0.96 nd nd 0.16 0.68 0.16 nd nd 0.48 nCohort 1 95 nd nd 95 108 82 nd nd 82 nCohort 2 2 nd nd 15 3 14 nd nd 2 Cutoff 1 0.000172 nd nd 0.00862 0.00573 0.00862 nd nd 0.00454 Sens 1 100%  nd nd 80% 100%  79% nd nd 100%  Spec 1 13% nd nd 40% 31% 44% nd nd 34% Cutoff 2 0.000172 nd nd 0.00862 0.00573 0.00454 nd nd 0.00454 Sens 2 100%  nd nd 80% 100%  86% nd nd 100%  Spec 2 13% nd nd 40% 31% 34% nd nd 34% Cutoff 3 0.000172 nd nd 0.00132 0.00573 0.00132 nd nd 0.00454 Sens 3 100%  nd nd 93% 100%  93% nd nd 100%  Spec 3 13% nd nd 27% 31% 32% nd nd 34% Cutoff 4 0.0197 nd nd 0.0197 0.0197 0.0197 nd nd 0.0197 Sens 4 50% nd nd 40%  0% 43% nd nd 50% Spec 4 73% nd nd 73% 70% 72% nd nd 72% Cutoff 5 0.0292 nd nd 0.0292 0.0292 0.0292 nd nd 0.0292 Sens 5 50% nd nd 13%  0% 14% nd nd 50% Spec 5 83% nd nd 83% 82% 83% nd nd 83% Cutoff 6 0.0423 nd nd 0.0423 0.0423 0.0423 nd nd 0.0423 Sens 6  0% nd nd  7%  0%  7% nd nd 50% Spec 6 92% nd nd 92% 91% 91% nd nd 91% OR Quart 2 0 nd nd 4.3 >1.0 >8.0 nd nd >1.0 p Value na nd nd 0.20 <1.0 <0.064 nd nd <0.97 95% CI of na nd nd 0.45 >0.059 >0.88 nd nd >0.061 OR Quart 2 na nd nd 42 na na nd nd na OR Quart 3 0 nd nd 5.9 >2.1 >3.4 nd nd >0 p Value na nd nd 0.12 <0.56 <0.30 nd nd <na 95% CI of na nd nd 0.64 >0.18 >0.33 nd nd >na OR Quart 3 na nd nd 54 na na nd nd na OR Quart 4 0.96 nd nd 5.7 >0 >6.3 nd nd >1.0 p Value 0.98 nd nd 0.13 <na <0.11 nd nd <0.97 95% CI of 0.057 nd nd 0.61 >na >0.68 nd nd >0.061 OR Quart 4 16 nd nd 52 na na nd nd na Alpha-1-antitrypsin Neutrophil elastase complex 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 16.2 272 16.2 43.9 16.2 10.7 Average 65.3 222 65.3 168 65.3 39.0 Stdev 120 142 120 184 120 44.5 p (t-test) 0.013 0.011 0.57 Min 0.946 14.8 0.946 2.36 0.946 1.04 Max 400 329 400 400 400 97.9 n (Samp) 93 4 93 12 93 7 n (Patient) 67 4 67 12 67 7 sCr only Median 17.7 154 17.7 206 17.7 5.41 Average 73.1 154 73.1 206 73.1 136 Stdev 124 196 124 274 124 229 p (t-test) 0.37 0.14 0.40 Min 0.946 14.8 0.946 12.3 0.946 1.23 Max 400 292 400 400 400 400 n (Samp) 117 2 117 2 117 3 n (Patient) 83 2 83 2 83 3 UO only Median 17.3 252 17.3 55.1 17.3 38.5 Average 80.5 198 80.5 172 80.5 46.8 Stdev 137 165 137 176 137 43.7 p (t-test) 0.15 0.048 0.55 Min 1.27 12.7 1.27 2.36 1.27 1.04 Max 400 329 400 400 400 97.9 n (Samp) 80 3 80 11 80 6 n (Patient) 59 3 59 11 59 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.79 0.67 0.71 0.70 0.68 0.69 0.45 0.39 0.53 SE 0.14 0.21 0.17 0.088 0.21 0.093 0.12 0.18 0.12 p 0.032 0.43 0.22 0.024 0.38 0.043 0.64 0.54 0.80 nCohort 1 93 117 80 93 117 80 93 117 80 nCohort 2 4 2 3 12 2 11 7 3 6 Cutoff 1 245 14.5 12.7 18.0 12.2 20.3 5.27 1.04 10.4 Sens 1 75% 100%  100%  75% 100%  73% 71% 100%  83% Spec 1 89% 44% 42% 55% 41% 59% 23%  2% 34% Cutoff 2 14.5 14.5 12.7 16.2 12.2 18.0 1.04 1.04 10.4 Sens 2 100%  100%  100%  83% 100%  82% 86% 100%  83% Spec 2 49% 44% 42% 51% 41% 52%  1%  2% 34% Cutoff 3 14.5 14.5 12.7 12.2 12.2 16.2 0.946 1.04 0 Sens 3 100%  100%  100%  92% 100%  91% 100%  100%  100%  Spec 3 49% 44% 42% 45% 41% 48%  1%  2%  0% Cutoff 4 31.8 42.5 31.9 31.8 42.5 31.9 31.8 42.5 31.9 Sens 4 75% 50% 67% 58% 50% 64% 43% 33% 50% Spec 4 71% 70% 70% 71% 70% 70% 71% 70% 70% Cutoff 5 57.4 76.0 76.0 57.4 76.0 76.0 57.4 76.0 76.0 Sens 5 75% 50% 67% 42% 50% 45% 43% 33% 33% Spec 5 81% 80% 80% 81% 80% 80% 81% 80% 80% Cutoff 6 347 347 400 347 347 400 347 347 400 Sens 6  0%  0%  0% 33% 50%  0%  0% 33%  0% Spec 6 90% 91% 100%  90% 91% 100%  90% 91% 100%  OR Quart 2 >1.0 >1.0 >1.0 2.1 >1.0 2.0 0 0 2.0 p Value <0.98 <1.0 <1.0 0.56 <1.0 0.58 na na 0.58 95% CI of >0.062 >0.060 >0.058 0.18 >0.060 0.17 na na 0.17 OR Quart 2 na na na 25 na 24 na na 24 OR Quart 3 >0 >0 >0 3.3 >0 3.1 0.31 0 0 p Value <na <na <na 0.32 <na 0.34 0.32 na na 95% CI of >na >na >na 0.32 >na 0.30 0.030 na na OR Quart 3 na na na 34 na 33 3.2 na na OR Quart 4 >3.3 >1.0 >2.1 7.1 >1.0 5.8 1.0 2.1 3.2 p Value <0.32 <1.0 <0.56 0.079 <1.0 0.12 1.0 0.56 0.34 95% CI of >0.32 >0.060 >0.18 0.80 >0.060 0.62 0.18 0.18 0.30 OR Quart 4 na na na 64 na 55 5.5 24 33 Interstitial collagenase:Metalloproteinase inhibitor 2 complex 24 hr prior to AKI stage Cohort 1 Cohort 2 sCr or UO Median 0.233 0.233 Average 177 26.6 Stdev 1620 76.2 p (t-test) 0.72 Min 0.228 0.228 Max 16000 297 n (Samp) 97 15 n (Patient) 74 15 sCr only Median 0.233 6.97 Average 159 12.2 Stdev 1530 15.3 p (t-test) 0.87 Min 0.228 0.233 Max 16000 29.5 n (Samp) 110 3 n (Patient) 85 3 24 hr prior to AKI stage 48 hr prior to AKI stage UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 0.233 0.233 0.233 0.231 Average 202 28.0 202 0.231 Stdev 1770 78.9 1770 0.00389 p (t-test) 0.71 0.87 Min 0.228 0.228 0.228 0.228 Max 16000 297 16000 0.233 n (Samp) 82 14 82 2 n (Patient) 62 14 62 2 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.55 0.78 0.51 nd nd 0.34 SE 0.082 0.16 0.084 nd nd 0.21 p 0.51 0.079 0.94 nd nd 0.47 nCohort 1 97 110 82 nd nd 82 nCohort 2 15 3 14 nd nd 2 Cutoff 1 0 0.228 0 nd nd 0 Sens 1 100%  100%  100%  nd nd 100%  Spec 1  0% 37%  0% nd nd  0% Cutoff 2 0 0.228 0 nd nd 0 Sens 2 100%  100%  100%  nd nd 100%  Spec 2  0% 37%  0% nd nd  0% Cutoff 3 0 0.228 0 nd nd 0 Sens 3 100%  100%  100%  nd nd 100%  Spec 3  0% 37%  0% nd nd  0% Cutoff 4 0.233 0.233 0.233 nd nd 0.233 Sens 4 40% 67% 36% nd nd  0% Spec 4 81% 79% 79% nd nd 79% Cutoff 5 0.233 1.35 1.26 nd nd 1.26 Sens 5 40% 67% 36% nd nd  0% Spec 5 81% 80% 80% nd nd 80% Cutoff 6 18.2 18.5 10.7 nd nd 10.7 Sens 6 20% 33% 21% nd nd  0% Spec 6 91% 91% 90% nd nd 90% OR Quart 2 0.17 >0 1.0 nd nd >0 p Value 0.12 <na 1.0 nd nd <na 95% CI of 0.019 >na 0.22 nd nd >na OR Quart 2 1.6 na 4.6 nd nd na OR Quart 3 0.55 >1.0 0.22 nd nd >1.0 p Value 0.45 <0.98 0.19 nd nd <0.97 95% CI of 0.12 >0.062 0.022 nd nd >0.061 OR Quart 3 2.6 na 2.1 nd nd na OR Quart 4 1.3 >2.1 1.3 nd nd >1.0 p Value 0.74 <0.56 0.71 nd nd <0.97 95% CI of 0.33 >0.18 0.31 nd nd >0.061 OR Quart 4 4.7 na 5.6 nd nd na 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 28.1 269 nd nd Average 585 1600 nd nd Stdev 1940 4100 nd nd p (t-test) 0.12 nd nd Min 1.15 1.15 nd nd Max 16000 16000 nd nd n (Samp) 91 15 nd nd n (Patient) 72 15 nd nd sCr only Median 30.3 527 nd nd Average 817 447 nd nd Stdev 2580 245 nd nd p (t-test) 0.81 nd nd Min 1.15 171 nd nd Max 16000 642 nd nd n (Samp) 105 3 nd nd n (Patient) 84 3 nd nd UO only Median 16.2 231 16.2 5640 Average 624 1660 624 5640 Stdev 2060 4240 2060 7740 p (t-test) 0.15 0.0023 Min 1.15 1.15 1.15 171 Max 16000 16000 16000 11100 n (Samp) 80 14 80 2 n (Patient) 63 14 63 2 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.60 0.75 0.57 nd nd 0.83 SE 0.083 0.17 0.086 nd nd 0.18 p 0.22 0.14 0.40 nd nd 0.066 nCohort 1 91 105 80 nd nd 80 nCohort 2 15 3 14 nd nd 2 Cutoff 1 1.15 164 1.15 nd nd 164 Sens 1 80% 100%  79% nd nd 100%  Spec 1 18% 65% 15% nd nd 68% Cutoff 2 1.15 164 0 nd nd 164 Sens 2 80% 100%  100%  nd nd 100%  Spec 2 18% 65%  0% nd nd 68% Cutoff 3 0 164 0 nd nd 164 Sens 3 100%  100%  100%  nd nd 100%  Spec 3  0% 65%  0% nd nd 68% Cutoff 4 189 295 227 nd nd 227 Sens 4 60% 67% 50% nd nd 50% Spec 4 70% 70% 70% nd nd 70% Cutoff 5 579 595 579 nd nd 579 Sens 5 33% 33% 29% nd nd 50% Spec 5 80% 80% 80% nd nd 80% Cutoff 6 1380 1700 1380 nd nd 1380 Sens 6 20%  0% 21% nd nd 50% Spec 6 90% 90% 90% nd nd 90% OR Quart 2 0.21 >0 0.61 nd nd >0 p Value 0.18 <na 0.60 nd nd <na 95% CI of 0.022 >na 0.092 nd nd >na OR Quart 2 2.0 na 4.0 nd nd na OR Quart 3 1.0 >1.0 1.4 nd nd >1.1 p Value 1.0 <0.98 0.68 nd nd <0.97 95% CI of 0.22 >0.062 0.28 nd nd >0.061 OR Quart 3 4.5 na 7.1 nd nd na OR Quart 4 1.6 >2.2 1.8 nd nd >1.0 p Value 0.53 <0.54 0.48 nd nd <1.0 95% CI of 0.39 >0.18 0.37 nd nd >0.058 OR Quart 4 6.4 na 8.4 nd nd na Neural cell adhesion molecule 1 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 2660 3570 2660 2810 2660 2310 Average 3280 3960 3280 4330 3280 2870 Stdev 2980 2720 2980 6820 2980 2250 p (t-test) 0.087 0.014 0.39 Min 6.83 85.5 6.83 375 6.83 138 Max 48400 15000 48400 55700 48400 9700 n (Samp) 923 60 923 68 923 38 n (Patient) 359 60 359 68 359 38 sCr only Median 2820 2420 2820 2620 2820 2470 Average 3470 2380 3470 3790 3470 3290 Stdev 3270 1460 3270 2950 3270 2340 p (t-test) 0.20 0.68 0.83 Min 6.83 301 6.83 921 6.83 932 Max 55700 4670 55700 10800 55700 8410 n (Samp) 1219 15 1219 18 1219 16 n (Patient) 439 15 439 18 439 16 UO only Median 2740 4130 2740 3060 2740 2460 Average 3340 4790 3340 4830 3340 2990 Stdev 2980 4070 2980 7620 2980 2240 p (t-test) 6.9E−4 0.0014 0.50 Min 0.234 85.5 0.234 375 0.234 138 Max 48400 26600 48400 55700 48400 9700 n (Samp) 819 55 819 61 819 34 n (Patient) 285 55 285 61 285 34 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.59 0.39 0.64 0.54 0.52 0.55 0.44 0.48 0.46 SE 0.040 0.078 0.041 0.037 0.070 0.039 0.049 0.073 0.052 p 0.029 0.15 8.7E−4 0.30 0.73 0.24 0.24 0.83 0.41 nCohort 1 923 1219 819 923 1219 819 923 1219 819 nCohort 2 60 15 55 68 18 61 38 16 34 Cutoff 1 2430 1120 2720 2030 2080 2030 1250 1050 1650 Sens 1 70% 73% 71% 71% 72% 70% 71% 75% 71% Spec 1 46% 14% 50% 36% 35% 34% 17% 12% 26% Cutoff 2 1680 848 2290 1210 1700 1220 957 965 1180 Sens 2 80% 80% 80% 81% 83% 80% 82% 81% 82% Spec 2 28%  8% 41% 16% 26% 15% 11% 10% 15% Cutoff 3 873 615 1220 1040 1080 1040 402 950 402 Sens 3 90% 93% 91% 91% 94% 90% 92% 94% 91% Spec 3  8%  4% 15% 13% 12% 11%  2% 10%  2% Cutoff 4 3890 4060 3930 3890 4060 3930 3890 4060 3930 Sens 4 45%  7% 53% 38% 39% 41% 26% 38% 26% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 4730 4960 4750 4730 4960 4750 4730 4960 4750 Sens 5 35%  0% 44% 28% 28% 31% 21% 25% 21% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 6230 6520 6280 6230 6520 6280 6230 6520 6280 Sens 6 20%  0% 24% 16% 17% 18%  8%  6%  9% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 0.65 6.1 1.7 1.1 2.0 1.2 0.49 0.40 0.66 p Value 0.36 0.094 0.25 0.72 0.32 0.56 0.20 0.27 0.44 95% CI of 0.26 0.73 0.67 0.56 0.50 0.59 0.17 0.076 0.23 OR Quart 2 1.6 51 4.5 2.3 8.1 2.7 1.5 2.1 1.9 OR Quart 3 1.5 2.0 1.8 0.93 1.3 0.84 1.1 0.80 1.1 p Value 0.27 0.57 0.25 0.84 0.70 0.67 0.82 0.74 0.81 95% CI of 0.72 0.18 0.68 0.44 0.30 0.37 0.46 0.21 0.45 OR Quart 3 3.3 22 4.5 2.0 6.0 1.9 2.7 3.0 2.8 OR Quart 4 1.9 6.1 3.7 1.5 1.7 1.7 1.2 1.0 1.0 p Value 0.082 0.094 0.0029 0.24 0.48 0.16 0.66 1.00 0.99 95% CI of 0.92 0.73 1.6 0.76 0.40 0.82 0.52 0.29 0.39 OR Quart 4 3.9 51 8.8 3.0 7.1 3.4 2.9 3.5 2.6 Myeloid differentiation primary response protein MyD88 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.000533 0.000352 0.000533 0.000533 0.000533 0.00237 Average 0.0158 0.0168 0.0158 0.0123 0.0158 0.00355 Stdev 0.0587 0.0263 0.0587 0.0363 0.0587 0.00366 p (t-test) 0.96 0.78 0.64 Min 0.000126 0.000126 0.000126 0.000126 0.000126 0.000171 Max 0.671 0.0804 0.671 0.171 0.671 0.00853 n (Samp) 197 10 197 23 197 5 n (Patient) 118 10 118 23 118 5 sCr only Median nd nd 0.000533 0.000168 nd nd Average nd nd 0.0165 0.000259 nd nd Stdev nd nd 0.0575 0.000183 nd nd p (t-test) nd nd 0.57 nd nd Min nd nd 0.000126 0.000165 nd nd Max nd nd 0.671 0.000533 nd nd n (Samp) nd nd 239 4 nd nd n (Patient) nd nd 138 4 nd nd UO only Median 0.000533 0.000352 0.000533 0.000533 0.000533 0.00145 Average 0.0131 0.0168 0.0131 0.0128 0.0131 0.00305 Stdev 0.0363 0.0263 0.0363 0.0370 0.0363 0.00350 p (t-test) 0.75 0.97 0.50 Min 0.000126 0.000126 0.000126 0.000126 0.000126 0.000171 Max 0.371 0.0804 0.371 0.171 0.371 0.00853 n (Samp) 181 10 181 22 181 6 n (Patient) 105 10 105 22 105 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.54 nd 0.53 0.46 0.34 0.46 0.62 nd 0.60 SE 0.095 nd 0.096 0.065 0.15 0.066 0.14 nd 0.12 p 0.71 nd 0.74 0.49 0.28 0.56 0.36 nd 0.42 nCohort 1 197 nd 181 197 239 181 197 nd 181 nCohort 2 10 nd 10 23 4 22 5 nd 6 Cutoff 1 0.000165 nd 0.000165 0.000126 0.000126 0.000126 0.000171 nd 0.000171 Sens 1 80% nd 80% 91% 100%  91% 80% nd 83% Spec 1 35% nd 33% 10% 10% 10% 42% nd 41% Cutoff 2 0.000165 nd 0.000165 0.000126 0.000126 0.000126 0.000171 nd 0.000171 Sens 2 80% nd 80% 91% 100%  91% 80% nd 83% Spec 2 35% nd 33% 10% 10% 10% 42% nd 41% Cutoff 3 0 nd 0 0.000126 0.000126 0.000126 0.000165 nd 0.000165 Sens 3 100%  nd 100%  91% 100%  91% 100%  nd 100%  Spec 3  0% nd  0% 10% 10% 10% 35% nd 33% Cutoff 4 0.00167 nd 0.00309 0.00167 0.00309 0.00309 0.00167 nd 0.00309 Sens 4 40% nd 40% 22%  0% 23% 60% nd 33% Spec 4 70% nd 70% 70% 70% 70% 70% nd 70% Cutoff 5 0.0184 nd 0.0188 0.0184 0.0188 0.0188 0.0184 nd 0.0188 Sens 5 40% nd 40% 17%  0% 18%  0% nd  0% Spec 5 80% nd 80% 80% 80% 80% 80% nd 80% Cutoff 6 0.0387 nd 0.0366 0.0387 0.0393 0.0366 0.0387 nd 0.0366 Sens 6 10% nd 10%  9%  0%  9%  0% nd  0% Spec 6 90% nd 90% 90% 90% 90% 90% nd 90% OR Quart 2 2.0 nd 1.5 0 >1.0 0.38 >1.0 nd >3.1 p Value 0.42 nd 0.67 na <0.99 0.26 <1.0 nd <0.33 95% CI of 0.36 nd 0.24 na >0.062 0.069 >0.061 nd >0.31 OR Quart 2 12 nd 9.4 na na 2.0 na nd na OR Quart 3 0 nd 0.48 3.1 >3.2 1.2 >3.2 nd >3.1 p Value na nd 0.55 0.046 <0.33 0.75 <0.32 nd <0.33 95% CI of na nd 0.042 1.0 >0.32 0.35 >0.32 nd >0.31 OR Quart 3 na nd 5.5 9.4 na 4.3 na nd na OR Quart 4 2.0 nd 2.0 1.0 >0 2.0 >1.0 nd >0 p Value 0.42 nd 0.42 1.0 <na 0.24 <1.0 nd <na 95% CI of 0.36 nd 0.36 0.27 >na 0.63 >0.061 nd >na OR Quart 4 12 nd 12 3.7 na 6.5 na nd na

TABLE 3 Comparison of marker levels in urine samples collected within 12 hours of reaching stage R from Cohort 1 (patients that reached, but did not progress beyond, RIFLE stage R) and from Cohort 2 (patients that reached RIFLE stage I or F). Tumor necrosis factor ligand superfamily member 10 sCr or UO sCr only UO only Cohort Cohort Cohort Cohort Cohort 1 2 Cohort 1 2 1 2 Median 0.0287 0.0287 0.0257 0.0285 0.0335 0.0286 Average 1.65 2.49 0.779 0.732 2.34 2.49 Stdev 7.15 8.75 2.82 1.39 8.97 9.35 p (t-test) 0.53 0.96 0.93 Min 0.0110 0.0110 0.0139 0.0139 0.0110 0.0110 Max 63.9 50.6 13.9 3.82 63.9 50.6 n (Samp) 121 43 47 11 99 30 n (Patient) 121 43 47 11 99 30 At Enrollment sCr or UO sCr only UO only AUC 0.53 0.59 0.49 SE 0.052 0.099 0.061 p 0.61 0.36 0.88 nCohort 1 121 47 99 nCohort 2 43 11 30 Cutoff 1 0.0239 0.0237 0.0239 Sens 1 77% 73% 73% Spec 1 35% 47% 32% Cutoff 2 0.0227 0.0227 0.0227 Sens 2 84% 82% 83% Spec 2 30% 38% 28% Cutoff 3 0.0159 0.0139 0.0159 Sens 3 91% 91% 90% Spec 3 15%  6% 15% Cutoff 4 0.0439 0.0363 0.0439 Sens 4 26% 36% 20% Spec 4 73% 74% 73% Cutoff 5 0.0526 0.0439 0.0526 Sens 5 21% 36% 17% Spec 5 85% 81% 84% Cutoff 6 1.70 2.23 1.70 Sens 6 16% 18% 17% Spec 6 90% 91% 91% OR Quart 2 2.8 0.92 1.3 p Value 0.050 0.94 0.71 95% CI of 1.00 0.11 0.37 OR Quart 2 7.9 7.6 4.3 OR Quart 3 1.6 1.6 3.1 p Value 0.42 0.62 0.051 95% CI of 0.53 0.23 0.99 OR Quart 3 4.6 12 9.5 OR Quart 4 1.8 2.2 0.64 p Value 0.29 0.42 0.53 95% CI of 0.61 0.33 0.16 OR Quart 4 5.2 14 2.5

TABLE 4 Comparison of the maximum marker levels in urine samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0) and the maximum values in urine samples collected from subjects between enrollment and 0, 24 hours, and 48 hours prior to reaching stage F in Cohort 2. Stromelysin-1:Metalloproteinase inhibitor 2 complex 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.487 0.487 0.487 0.487 0.487 0.487 Average 400 101 400 101 400 0.487 Stdev 2140 197 2140 197 2140 0 p (t-test) 0.70 0.70 0.75 Min 0.237 0.487 0.237 0.487 0.237 0.487 Max 13900 530 13900 530 13900 0.487 n (Samp) 42 8 42 8 42 3 n (Patient) 42 8 42 8 42 3 sCr only Median 0.487 5.71 0.487 5.71 nd nd Average 238 136 238 136 nd nd Stdev 1630 263 1630 263 nd nd p (t-test) 0.90 0.90 nd nd Min 0.237 0.487 0.237 0.487 nd nd Max 13900 530 13900 530 nd nd n (Samp) 73 4 73 4 nd nd n (Patient) 73 4 73 4 nd nd UO only Median 0.487 0.487 0.487 0.487 0.487 0.487 Average 435 53.8 435 53.8 435 0.487 Stdev 2350 119 2350 119 2350 0 p (t-test) 0.72 0.72 0.75 Min 0.237 0.487 0.237 0.487 0.237 0.487 Max 13900 267 13900 267 13900 0.487 n (Samp) 35 5 35 5 35 3 n (Patient) 35 5 35 5 35 3 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.68 0.76 0.69 0.68 0.76 0.69 0.56 nd 0.63 SE 0.11 0.14 0.14 0.11 0.14 0.14 0.18 nd 0.18 p 0.11 0.076 0.17 0.11 0.076 0.17 0.74 nd 0.48 nCohort 1 42 73 35 42 73 35 42 nd 35 nCohort 2 8 4 5 8 4 5 3 nd 3 Cutoff 1 0.237 0.237 0.237 0.237 0.237 0.237 0.237 nd 0.237 Sens 1 100%  100%  100%  100%  100%  100%  100%  nd 100%  Spec 1 31% 42% 46% 31% 42% 46% 31% nd 46% Cutoff 2 0.237 0.237 0.237 0.237 0.237 0.237 0.237 nd 0.237 Sens 2 100%  100%  100%  100%  100%  100%  100%  nd 100%  Spec 2 31% 42% 46% 31% 42% 46% 31% nd 46% Cutoff 3 0.237 0.237 0.237 0.237 0.237 0.237 0.237 nd 0.237 Sens 3 100%  100%  100%  100%  100%  100%  100%  nd 100%  Spec 3 31% 42% 46% 31% 42% 46% 31% nd 46% Cutoff 4 0.487 0.487 0.487 0.487 0.487 0.487 0.487 nd 0.487 Sens 4 38% 50% 20% 38% 50% 20%  0% nd  0% Spec 4 81% 82% 80% 81% 82% 80% 81% nd 80% Cutoff 5 0.487 0.487 0.487 0.487 0.487 0.487 0.487 nd 0.487 Sens 5 38% 50% 20% 38% 50% 20%  0% nd  0% Spec 5 81% 82% 80% 81% 82% 80% 81% nd 80% Cutoff 6 261 154 201 261 154 201 261 nd 201 Sens 6 25% 25% 20% 25% 25% 20%  0% nd  0% Spec 6 90% 90% 91% 90% 90% 91% 90% nd 91% OR Quart 2 >7.5 >2.2 >6.7 >7.5 >2.2 >6.7 >4.1 nd >3.9 p Value <0.090 <0.53 <0.12 <0.090 <0.53 <0.12 <0.25 nd <0.28 95% CI of >0.73 >0.19 >0.60 >0.73 >0.19 >0.60 >0.36 nd >0.33 OR Quart 2 na na na na na na na nd na OR Quart 3 >0 >0 >0 >0 >0 >0 >0 nd >0 p Value <na <na <na <na <na <na <na nd <na 95% CI of >na >na >na >na >na >na >na nd >na OR Quart 3 na na na na na na na nd na OR Quart 4 >3.6 >2.1 >1.1 >3.6 >2.1 >1.1 >0 nd >0 p Value <0.30 <0.56 <0.94 <0.30 <0.56 <0.94 <na nd <na 95% CI of >0.32 >0.18 >0.060 >0.32 >0.18 >0.060 >na nd >na OR Quart 4 na na na na na na na nd na Heat shock 70 kDa protein 1 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 338 1320 338 1320 338 1320 Average 633 2600 633 2600 633 4450 Stdev 1230 4080 1230 4080 1230 6370 p (t-test) 0.013 0.013 0.0012 Min 0.297 250 0.297 250 0.297 250 Max 7800 11800 7800 11800 7800 11800 n (Samp) 41 7 41 7 41 3 n (Patient) 41 7 41 7 41 3 sCr only Median 408 1300 408 1300 nd nd Average 620 1140 620 1140 nd nd Stdev 1040 648 1040 648 nd nd p (t-test) 0.33 0.33 nd nd Min 0.297 250 0.297 250 nd nd Max 7800 1710 7800 1710 nd nd n (Samp) 71 4 71 4 nd nd n (Patient) 71 4 71 4 nd nd UO only Median 277 934 277 934 277 1320 Average 664 3480 664 3480 664 4450 Stdev 1330 5560 1330 5560 1330 6370 p (t-test) 0.013 0.013 0.0031 Min 0.297 250 0.297 250 0.297 250 Max 7800 11800 7800 11800 7800 11800 n (Samp) 35 4 35 4 35 3 n (Patient) 35 4 35 4 35 3 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.83 0.80 0.75 0.83 0.80 0.75 0.79 nd 0.79 SE 0.099 0.14 0.15 0.099 0.14 0.15 0.16 nd 0.16 p 8.2E−4 0.027 0.084 8.2E−4 0.027 0.084 0.066 nd 0.077 nCohort 1 41 71 35 41 71 35 41 nd 35 nCohort 2 7 4 4 7 4 4 3 nd 3 Cutoff 1 1020 1040 512 1020 1040 512 245 nd 225 Sens 1 71% 75% 75% 71% 75% 75% 100%  nd 100%  Spec 1 88% 90% 66% 88% 90% 66% 46% nd 49% Cutoff 2 512 245 225 512 245 225 245 nd 225 Sens 2 86% 100%  100%  86% 100%  100%  100%  nd 100%  Spec 2 66% 41% 49% 66% 41% 49% 46% nd 49% Cutoff 3 245 245 225 245 245 225 245 nd 225 Sens 3 100%  100%  100%  100%  100%  100%  100%  nd 100%  Spec 3 46% 41% 49% 46% 41% 49% 46% nd 49% Cutoff 4 596 627 596 596 627 596 596 nd 596 Sens 4 71% 75% 50% 71% 75% 50% 67% nd 67% Spec 4 71% 70% 71% 71% 70% 71% 71% nd 71% Cutoff 5 811 812 755 811 812 755 811 nd 755 Sens 5 71% 75% 50% 71% 75% 50% 67% nd 67% Spec 5 80% 80% 80% 80% 80% 80% 80% nd 80% Cutoff 6 1150 1040 1340 1150 1040 1340 1150 nd 1340 Sens 6 57% 75% 25% 57% 75% 25% 67% nd 33% Spec 6 90% 90% 91% 90% 90% 91% 90% nd 91% OR Quart 2 >1.1 >1.0 >1.0 >1.1 >1.0 >1.0 >1.1 nd >1.0 p Value <0.95 <1.0 <1.0 <0.95 <1.0 <1.0 <0.95 nd <1.0 95% CI of >0.061 >0.058 >0.054 >0.061 >0.058 >0.054 >0.060 nd >0.054 OR Quart 2 na na na na na na na nd na OR Quart 3 >1.1 >0 >1.0 >1.1 >0 >1.0 >0 nd >0 p Value <0.95 <na <1.0 <0.95 <na <1.0 <na nd <na 95% CI of >0.061 >na >0.054 >0.061 >na >0.054 >na nd >na OR Quart 3 na na na na na na na nd na OR Quart 4 >8.6 >3.4 >2.2 >8.6 >3.4 >2.2 >2.4 nd >2.2 p Value <0.072 <0.31 <0.54 <0.072 <0.31 <0.54 <0.49 nd <0.54 95% CI of >0.83 >0.32 >0.17 >0.83 >0.32 >0.17 >0.19 nd >0.17 OR Quart 4 na na na na na na na nd na Interstitial collagenase:Metalloproteinase inhibitor 2 complex 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.233 6.57 0.233 6.57 0.233 0.228 Average 396 48.1 396 48.1 396 2.21 Stdev 2470 102 2470 102 2470 3.43 p (t-test) 0.69 0.69 0.79 Min 0.228 0.228 0.228 0.228 0.228 0.228 Max 16000 297 16000 297 16000 6.17 n (Samp) 42 8 42 8 42 3 n (Patient) 42 8 42 8 42 3 sCr only Median 0.233 6.57 0.233 6.57 nd nd Average 233 10.7 233 10.7 nd nd Stdev 1870 12.9 1870 12.9 nd nd p (t-test) 0.81 0.81 nd nd Min 0.228 0.233 0.228 0.233 nd nd Max 16000 29.5 16000 29.5 nd nd n (Samp) 73 4 73 4 nd nd n (Patient) 73 4 73 4 nd nd UO only Median 0.233 6.17 0.233 6.17 0.233 0.228 Average 462 69.6 462 69.6 462 2.21 Stdev 2700 129 2700 129 2700 3.43 p (t-test) 0.75 0.75 0.77 Min 0.228 0.228 0.228 0.228 0.228 0.228 Max 16000 297 16000 297 16000 6.17 n (Samp) 35 5 35 5 35 3 n (Patient) 35 5 35 5 35 3 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.68 0.77 0.59 0.68 0.77 0.59 0.41 nd 0.35 SE 0.11 0.14 0.14 0.11 0.14 0.14 0.18 nd 0.18 p 0.12 0.055 0.51 0.12 0.055 0.51 0.63 nd 0.41 nCohort 1 42 73 35 42 73 35 42 nd 35 nCohort 2 8 4 5 8 4 5 3 nd 3 Cutoff 1 0.228 5.57 0 0.228 5.57 0 0 nd 0 Sens 1 75% 75% 100%  75% 75% 100%  100%  nd 100%  Spec 1 45% 79%  0% 45% 79%  0%  0% nd  0% Cutoff 2 0 0.228 0 0 0.228 0 0 nd 0 Sens 2 100%  100%  100%  100%  100%  100%  100%  nd 100%  Spec 2  0% 36%  0%  0% 36%  0%  0% nd  0% Cutoff 3 0 0.228 0 0 0.228 0 0 nd 0 Sens 3 100%  100%  100%  100%  100%  100%  100%  nd 100%  Spec 3  0% 36%  0%  0% 36%  0%  0% nd  0% Cutoff 4 0.233 0.233 0.233 0.233 0.233 0.233 0.233 nd 0.233 Sens 4 62% 75% 60% 62% 75% 60% 33% nd 33% Spec 4 76% 75% 71% 76% 75% 71% 76% nd 71% Cutoff 5 6.97 6.17 7.29 6.97 6.17 7.29 6.97 nd 7.29 Sens 5 38% 50% 40% 38% 50% 40%  0% nd  0% Spec 5 81% 82% 80% 81% 82% 80% 81% nd 80% Cutoff 6 30.3 30.3 18.5 30.3 30.3 18.5 30.3 nd 18.5 Sens 6 25%  0% 40% 25%  0% 40%  0% nd  0% Spec 6 90% 90% 91% 90% 90% 91% 90% nd 91% OR Quart 2 0 >0 0 0 >0 0 0 nd 0 p Value na <na na na <na na na nd na 95% CI of na >na na na >na na na nd na OR Quart 2 na na na na na na na nd na OR Quart 3 1.0 >1.1 0.44 1.0 >1.1 0.44 0 nd 0 p Value 1.0 <0.97 0.54 1.0 <0.97 0.54 na nd na 95% CI of 0.12 >0.061 0.034 0.12 >0.061 0.034 na nd na OR Quart 3 8.6 na 5.9 8.6 na 5.9 na nd na OR Quart 4 2.2 >3.4 1.0 2.2 >3.4 1.0 2.4 nd 2.6 p Value 0.42 <0.31 1.0 0.42 <0.31 1.0 0.49 nd 0.48 95% CI of 0.33 >0.32 0.11 0.33 >0.32 0.11 0.19 nd 0.19 OR Quart 4 15 na 8.9 15 na 8.9 32 nd 34 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 117 411 117 411 117 269 Average 756 2460 756 2460 756 685 Stdev 2540 5500 2540 5500 2540 961 p (t-test) 0.17 0.17 0.96 Min 1.15 1.15 1.15 1.15 1.15 1.15 Max 16000 16000 16000 16000 16000 1780 n (Samp) 40 8 40 8 40 3 n (Patient) 40 8 40 8 40 3 sCr only Median 110 398 110 398 nd nd Average 889 402 889 402 nd nd Stdev 2800 219 2800 219 nd nd p (t-test) 0.73 0.73 nd nd Min 1.15 171 1.15 171 nd nd Max 16000 642 16000 642 nd nd n (Samp) 72 4 72 4 nd nd n (Patient) 72 4 72 4 nd nd UO only Median 57.4 295 57.4 295 57.4 269 Average 772 3670 772 3670 772 685 Stdev 2710 6930 2710 6930 2710 961 p (t-test) 0.083 0.083 0.96 Min 1.15 1.15 1.15 1.15 1.15 1.15 Max 16000 16000 16000 16000 16000 1780 n (Samp) 35 5 35 5 35 3 n (Patient) 35 5 35 5 35 3 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.68 0.69 0.68 0.68 0.69 0.68 0.56 nd 0.57 SE 0.11 0.15 0.14 0.11 0.15 0.14 0.18 nd 0.18 p 0.099 0.21 0.21 0.099 0.21 0.21 0.73 nd 0.69 nCohort 1 40 72 35 40 72 35 40 nd 35 nCohort 2 8 4 5 8 4 5 3 nd 3 Cutoff 1 234 234 234 234 234 234 0 nd 0 Sens 1 75% 75% 80% 75% 75% 80% 100%  nd 100%  Spec 1 68% 64% 69% 68% 64% 69%  0% nd  0% Cutoff 2 164 164 234 164 164 234 0 nd 0 Sens 2 88% 100%  80% 88% 100%  80% 100%  nd 100%  Spec 2 57% 57% 69% 57% 57% 69%  0% nd  0% Cutoff 3 0 164 0 0 164 0 0 nd 0 Sens 3 100%  100%  100%  100%  100%  100%  100%  nd 100%  Spec 3  0% 57%  0%  0% 57%  0%  0% nd  0% Cutoff 4 398 419 398 398 419 398 398 nd 398 Sens 4 50% 50% 40% 50% 50% 40% 33% nd 33% Spec 4 70% 71% 71% 70% 71% 71% 70% nd 71% Cutoff 5 615 656 579 615 656 579 615 nd 579 Sens 5 38%  0% 40% 38%  0% 40% 33% nd 33% Spec 5 80% 81% 80% 80% 81% 80% 80% nd 80% Cutoff 6 1230 1380 1230 1230 1380 1230 1230 nd 1230 Sens 6 25%  0% 40% 25%  0% 40% 33% nd 33% Spec 6 90% 90% 91% 90% 90% 91% 90% nd 91% OR Quart 2 0 >0 0 0 >0 0 0 nd 0 p Value na <na na na <na na na nd na 95% CI of na >na na na >na na na nd na OR Quart 2 na na na na na na na nd na OR Quart 3 5.5 >3.6 2.2 5.5 >3.6 2.2 0.90 nd 1.0 p Value 0.16 <0.29 0.54 0.16 <0.29 0.54 0.94 nd 1.0 95% CI of 0.51 >0.34 0.17 0.51 >0.34 0.17 0.049 nd 0.053 OR Quart 3 59 na 30 59 na 30 17 nd 19 OR Quart 4 3.7 >1.1 2.2 3.7 >1.1 2.2 0.90 nd 0.89 p Value 0.29 <0.97 0.54 0.29 <0.97 0.54 0.94 nd 0.94 95% CI of 0.32 >0.061 0.17 0.32 >0.061 0.17 0.049 nd 0.047 OR Quart 4 42 na 30 42 na 30 17 nd 17 Neural cell adhesion molecule 1 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 2820 4940 2820 4490 2820 3900 Average 3370 6950 3370 6450 3370 4660 Stdev 2580 9680 2580 9690 2580 2330 p (t-test) 1.0E−5 1.4E−4 0.053 Min 6.83 171 6.83 171 6.83 1650 Max 22000 55700 22000 55700 22000 9700 n (Samp) 223 30 223 30 223 16 n (Patient) 223 30 223 30 223 16 sCr only Median 3740 4080 3740 4080 3740 5050 Average 4470 4560 4470 4510 4470 5290 Stdev 4470 2180 4470 2210 4470 1870 p (t-test) 0.95 0.97 0.63 Min 6.83 171 6.83 171 6.83 3280 Max 55700 7860 55700 7860 55700 7860 n (Samp) 374 13 374 13 374 7 n (Patient) 374 13 374 13 374 7 UO only Median 3220 5250 3220 5050 3220 4490 Average 3650 8910 3650 8250 3650 4750 Stdev 2320 11500 2320 11500 2320 2360 p (t-test) 2.8E−7 6.5E−6 0.090 Min 485 1700 485 1120 485 1650 Max 11700 55700 11700 55700 11700 9700 n (Samp) 172 23 172 23 172 14 n (Patient) 172 23 172 23 172 14 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.73 0.58 0.75 0.68 0.57 0.69 0.69 0.67 0.65 SE 0.054 0.084 0.061 0.056 0.084 0.064 0.076 0.11 0.082 p 1.9E−5 0.34 3.2E−5 0.0016 0.38 0.0035 0.013 0.13 0.074 nCohort 1 223 374 172 223 374 172 223 374 172 nCohort 2 30 13 23 30 13 23 16 7 14 Cutoff 1 3720 3410 3960 3110 3250 3110 3250 3970 3280 Sens 1 70% 77% 74% 70% 77% 74% 75% 71% 71% Spec 1 65% 46% 65% 57% 44% 49% 59% 56% 52% Cutoff 2 3250 3250 3280 2440 2870 2460 3110 3720 2690 Sens 2 80% 85% 83% 80% 85% 83% 81% 86% 86% Spec 2 59% 44% 52% 43% 37% 39% 57% 50% 43% Cutoff 3 2210 2200 2690 1740 2200 1740 1700 3250 1700 Sens 3 90% 92% 91% 90% 92% 91% 94% 100%  93% Spec 3 41% 27% 43% 27% 27% 22% 26% 44% 21% Cutoff 4 3940 5270 4360 3940 5270 4360 3940 5270 4360 Sens 4 63% 31% 65% 57% 31% 61% 50% 29% 50% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 4960 6450 5580 4960 6450 5580 4960 6450 5580 Sens 5 50% 23% 48% 47% 23% 43% 38% 29% 36% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 6160 7760 6670 6160 7760 6670 6160 7760 6670 Sens 6 33% 15% 35% 30% 15% 35% 25% 29% 21% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 1.5 4.1 4.2 2.1 4.1 1.3 2.0 >2.0 0.98 p Value 0.65 0.21 0.21 0.31 0.21 0.72 0.58 <0.56 0.98 95% CI of 0.25 0.45 0.45 0.50 0.45 0.28 0.18 >0.18 0.13 OR Quart 2 9.5 37 39 8.8 37 6.3 23 na 7.3 OR Quart 3 5.1 5.2 7.8 2.1 5.2 2.1 6.4 >3.1 2.7 p Value 0.043 0.14 0.059 0.31 0.14 0.32 0.089 <0.33 0.25 95% CI of 1.1 0.59 0.93 0.50 0.59 0.49 0.75 >0.32 0.49 OR Quart 3 25 45 66 8.8 45 8.9 55 na 15 OR Quart 4 10 3.0 14 6.1 3.0 3.8 7.7 >2.0 2.6 p Value 0.0027 0.34 0.014 0.0061 0.34 0.052 0.061 <0.57 0.27 95% CI of 2.2 0.31 1.7 1.7 0.31 0.99 0.91 >0.18 0.48 OR Quart 4 46 30 110 22 30 15 64 na 14 Tumor necrosis factor ligand superfamily member 10 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.0363 0.348 0.0363 0.338 0.0363 0.336 Average 4.58 11.4 4.58 10.8 4.58 1.86 Stdev 13.0 31.2 13.0 31.3 13.0 2.64 p (t-test) 0.032 0.048 0.40 Min 0.0110 0.0159 0.0110 0.0159 0.0110 0.0159 Max 92.3 134 92.3 134 92.3 8.63 n (Samp) 222 30 222 30 222 16 n (Patient) 222 30 222 30 222 16 sCr only Median 0.0410 0.0597 0.0410 0.0410 0.0410 0.636 Average 5.75 2.45 5.75 2.45 5.75 2.67 Stdev 16.4 3.54 16.4 3.54 16.4 3.52 p (t-test) 0.47 0.47 0.62 Min 0.0110 0.0159 0.0110 0.0159 0.0110 0.0159 Max 159 9.58 159 9.58 159 8.63 n (Samp) 379 13 379 13 379 7 n (Patient) 379 13 379 13 379 7 UO only Median 0.0439 1.51 0.0439 0.670 0.0439 0.336 Average 5.67 17.5 5.67 13.4 5.67 1.74 Stdev 15.3 37.7 15.3 35.4 15.3 2.70 p (t-test) 0.0059 0.064 0.34 Min 0.0110 0.0217 0.0110 0.0217 0.0110 0.0239 Max 92.3 134 92.3 134 92.3 9.58 n (Samp) 175 23 175 23 175 14 n (Patient) 175 23 175 23 175 14 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.63 0.55 0.63 0.61 0.52 0.61 0.59 0.56 0.56 SE 0.057 0.084 0.066 0.058 0.082 0.066 0.077 0.11 0.082 p 0.020 0.51 0.050 0.047 0.84 0.10 0.24 0.60 0.49 nCohort 1 222 379 175 222 379 175 222 379 175 nCohort 2 30 13 23 30 13 23 16 7 14 Cutoff 1 0.0335 0.0257 0.0335 0.0285 0.0239 0.0335 0.0285 0.0392 0.0335 Sens 1 70% 77% 74% 70% 85% 74% 75% 71% 71% Spec 1 48% 31% 39% 41% 27% 39% 41% 49% 39% Cutoff 2 0.0257 0.0239 0.0285 0.0239 0.0239 0.0285 0.0247 0.0217 0.0247 Sens 2 80% 85% 83% 80% 85% 83% 81% 86% 86% Spec 2 39% 27% 34% 39% 27% 34% 39% 20% 30% Cutoff 3 0.0239 0.0217 0.0239 0.0239 0.0217 0.0239 0.0237 0.0147 0.0239 Sens 3 90% 92% 91% 90% 92% 91% 94% 100%  93% Spec 3 38% 20% 30% 38% 20% 30% 38%  8% 30% Cutoff 4 0.775 1.53 1.42 0.775 1.53 1.42 0.775 1.53 1.42 Sens 4 47% 38% 52% 47% 38% 43% 44% 43% 36% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 4.08 5.16 4.69 4.08 5.16 4.69 4.08 5.16 4.69 Sens 5 27% 23% 30% 23% 23% 22% 12% 29%  7% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 11.8 16.4 15.0 11.8 16.4 15.0 11.8 16.4 15.0 Sens 6 13%  0% 22% 10%  0% 13%  0%  0%  0% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 12 1.5 4.5 6.5 2.0 4.5 4.1 0 >8.2 p Value 0.021 0.65 0.067 0.019 0.42 0.067 0.21 na <0.053 95% CI of 1.4 0.25 0.90 1.4 0.37 0.90 0.45 na >0.97 OR Quart 2 94 9.3 22 30 11 22 38 na na OR Quart 3 7.8 2.0 2.1 3.2 1.5 3.3 5.4 1.5 >3.2 p Value 0.059 0.42 0.41 0.16 0.65 0.16 0.13 0.65 <0.32 95% CI of 0.92 0.37 0.36 0.62 0.25 0.63 0.61 0.25 >0.32 OR Quart 3 65 11 12 17 9.3 17 47 9.3 na OR Quart 4 15 2.0 5.2 6.5 2.0 3.8 6.4 0.99 >4.3 p Value 0.011 0.42 0.043 0.019 0.42 0.11 0.089 0.99 <0.20 95% CI of 1.8 0.37 1.1 1.4 0.37 0.75 0.75 0.14 >0.46 OR Quart 4 120 11 25 30 11 19 55 7.2 na

TABLE 5 Comparison of marker levels in EDTA samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0) and in EDTA samples collected from subjects at 0, 24 hours, and 48 hours prior to reaching stage R, I or F in Cohort 2. Heat shock 70 kDa protein 1 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 641 1370 641 1200 641 2350 Average 1400 2760 1400 1990 1400 2240 Stdev 2010 3320 2010 2130 2010 2100 p (t-test) 0.057 0.25 0.26 Min 0.288 0.288 0.288 128 0.288 54.3 Max 10000 10700 10000 9450 10000 6660 n (Samp) 54 14 54 24 54 9 n (Patient) 53 14 53 24 53 9 sCr only Median 840 1950 840 1240 840 1720 Average 1580 2450 1580 1240 1580 1470 Stdev 2190 1690 2190 1030 2190 1030 p (t-test) 0.50 0.83 0.93 Min 0.288 1070 0.288 514 0.288 340 Max 10700 4330 10700 1970 10700 2350 n (Samp) 111 3 111 2 111 3 n (Patient) 93 3 93 2 93 3 UO only Median 641 1370 641 1220 641 963 Average 1390 2740 1390 2040 1390 2010 Stdev 1860 3550 1860 2110 1860 2200 p (t-test) 0.073 0.18 0.38 Min 0.288 0.288 0.288 128 0.288 54.3 Max 10000 10700 10000 9450 10000 6660 n (Samp) 48 12 48 25 48 9 n (Patient) 44 12 44 25 44 9 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.61 0.75 0.58 0.66 0.59 0.66 0.65 0.62 0.59 SE 0.088 0.17 0.095 0.070 0.21 0.070 0.11 0.18 0.11 p 0.21 0.13 0.43 0.023 0.69 0.025 0.16 0.49 0.39 nCohort 1 54 111 48 54 111 48 54 111 48 nCohort 2 14 3 12 24 2 25 9 3 9 Cutoff 1 705 1000 387 837 507 837 500 336 310 Sens 1 71% 100%  75% 71% 100%  72% 78% 100%  78% Spec 1 54% 56% 42% 56% 41% 54% 44% 31% 38% Cutoff 2 0.288 1000 0.288 514 507 664 310 336 248 Sens 2 86% 100%  83% 83% 100%  80% 89% 100%  89% Spec 2  4% 56%  4% 46% 41% 52% 37% 31% 29% Cutoff 3 0 1000 0 310 507 310 48.9 336 48.9 Sens 3 100%  100%  100%  92% 100%  92% 100%  100%  100%  Spec 3  0% 56%  0% 37% 41% 38% 11% 31% 12% Cutoff 4 1370 1500 1500 1370 1500 1500 1370 1500 1500 Sens 4 50% 67% 42% 46% 50% 48% 56% 67% 44% Spec 4 70% 70% 71% 70% 70% 71% 70% 70% 71% Cutoff 5 2700 2550 2700 2700 2550 2700 2700 2550 2700 Sens 5 36% 33% 33% 21%  0% 24% 33%  0% 33% Spec 5 81% 80% 81% 81% 80% 81% 81% 80% 81% Cutoff 6 3540 3540 3630 3540 3540 3630 3540 3540 3630 Sens 6 29% 33% 25% 12%  0% 12% 11%  0% 11% Spec 6 91% 90% 92% 91% 90% 92% 91% 90% 92% OR Quart 2 0.62 >0 0.62 3.6 >1.0 5.1 2.0 >1.0 3.5 p Value 0.63 <na 0.63 0.15 <0.98 0.068 0.59 <1.0 0.30 95% CI of 0.090 >na 0.087 0.63 >0.062 0.89 0.16 >0.060 0.32 OR Quart 2 4.3 na 4.3 21 na 29 25 na 39 OR Quart 3 1.0 >1.0 1.0 5.0 >0 6.4 0.93 >0 1.0 p Value 1.0 <0.98 1.0 0.071 <na 0.036 0.96 <na 1.0 95% CI of 0.17 >0.062 0.17 0.87 >na 1.1 0.053 >na 0.056 OR Quart 3 5.8 na 6.0 28 na 36 16 na 18 OR Quart 4 2.5 >2.1 1.5 7.0 >1.0 5.8 6.4 >2.1 4.7 p Value 0.25 <0.56 0.67 0.026 <1.0 0.046 0.11 <0.56 0.19 95% CI of 0.52 >0.18 0.26 1.3 >0.060 1.0 0.65 >0.18 0.46 OR Quart 4 13 na 8.0 38 na 33 63 na 49 Insulin-like growth factor 1 receptor 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.0498 0.0502 0.0498 0.0556 0.0498 0.0331 Average 0.207 0.622 0.207 0.470 0.207 0.899 Stdev 0.797 3.22 0.797 2.43 0.797 4.04 p (t-test) 0.28 0.38 0.15 Min 9.84E−5 0.000208 9.84E−5 0.000211 9.84E−5 0.000208 Max 6.23 18.2 6.23 14.8 6.23 19.4 n (Samp) 79 32 79 37 79 23 n (Patient) 70 32 70 37 70 23 sCr only Median 0.0498 0.0255 0.0498 0.0595 0.0498 0.0398 Average 0.124 2.30 0.124 1.92 0.124 2.20 Stdev 0.523 6.44 0.523 5.22 0.523 6.46 p (t-test) 1.0E−5 1.4E−5 2.5E−5 Min 9.84E−5 0.000208 9.84E−5 0.000211 9.84E−5 0.0214 Max 6.23 18.2 6.23 14.8 6.23 19.4 n (Samp) 187 8 187 8 187 9 n (Patient) 126 8 126 8 126 9 UO only Median 0.0498 0.0572 0.0498 0.0556 0.0498 0.0354 Average 0.233 0.808 0.233 0.589 0.233 0.0641 Stdev 0.851 3.96 0.851 3.27 0.851 0.126 p (t-test) 0.25 0.39 0.42 Min 0.000208 0.000208 0.000208 0.000211 0.000208 0.000208 Max 6.23 21.0 6.23 20.5 6.23 0.543 n (Samp) 69 28 69 39 69 17 n (Patient) 57 28 57 39 57 17 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.48 0.34 0.51 0.55 0.50 0.55 0.40 0.49 0.38 SE 0.061 0.11 0.065 0.058 0.10 0.058 0.070 0.099 0.080 p 0.72 0.14 0.82 0.37 0.98 0.35 0.17 0.93 0.14 nCohort 1 79 187 69 79 187 69 79 187 69 nCohort 2 32 8 28 37 8 39 23 9 17 Cutoff 1 0.0219 0.0137 0.0398 0.0373 0.00497 0.0373 0.0212 0.0283 0.0212 Sens 1 72% 75% 71% 73% 75% 74% 83% 78% 76% Spec 1 28% 14% 46% 43%  9% 43% 24% 28% 23% Cutoff 2 0.0178 0.000208 0.0212 0.0251 0.000211 0.0325 0.0212 0.0219 0.000224 Sens 2 81% 88% 82% 81% 88% 82% 83% 89% 82% Spec 2 20%  3% 23% 28%  5% 39% 24% 23%  7% Cutoff 3 0.0134 0.000172 0.0134 0.00497 0.000208 0.0178 0.000208 0.0212 0.000208 Sens 3 91% 100%  93% 92% 100%  92% 96% 100%  94% Spec 3 16%  1% 14% 10%  3% 22%  3% 18%  3% Cutoff 4 0.0839 0.0729 0.0839 0.0839 0.0729 0.0839 0.0839 0.0729 0.0839 Sens 4 16% 12% 21% 27% 25% 26%  9% 33%  6% Spec 4 73% 70% 72% 73% 70% 72% 73% 70% 72% Cutoff 5 0.0986 0.0876 0.101 0.0986 0.0876 0.101 0.0986 0.0876 0.101 Sens 5 12% 12% 14% 24% 25% 21%  9% 22%  6% Spec 5 81% 80% 81% 81% 80% 81% 81% 80% 81% Cutoff 6 0.135 0.133 0.176 0.135 0.133 0.176 0.135 0.133 0.176 Sens 6 12% 12%  7% 14% 25%  5%  9% 11%  6% Spec 6 91% 90% 91% 91% 90% 91% 91% 90% 91% OR Quart 2 2.0 1.0 1.0 1.4 0 2.1 3.8 0.49 8.4 p Value 0.24 1.0 1.0 0.56 na 0.24 0.13 0.57 0.060 95% CI of 0.62 0.061 0.27 0.44 na 0.62 0.69 0.043 0.91 OR Quart 2 6.7 16 3.7 4.5 na 6.8 21 5.6 77 OR Quart 3 1.5 2.0 2.1 1.9 0.98 3.2 6.4 2.1 6.2 p Value 0.54 0.57 0.22 0.26 0.98 0.050 0.028 0.41 0.11 95% CI of 0.43 0.18 0.63 0.62 0.19 1.00 1.2 0.36 0.66 OR Quart 3 5.0 23 7.3 6.0 5.1 11 33 12 58 OR Quart 4 1.5 4.4 0.95 1.7 0.64 2.1 3.8 1.0 6.6 p Value 0.49 0.20 0.94 0.39 0.63 0.24 0.13 1.0 0.10 95% CI of 0.45 0.47 0.26 0.53 0.10 0.62 0.69 0.14 0.70 OR Quart 4 5.2 41 3.5 5.2 4.0 6.8 21 7.4 62 Neural cell adhesion molecule 1 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 183000 192000 183000 180000 183000 172000 Average 191000 193000 191000 185000 191000 179000 Stdev 79300 67000 79300 78800 79300 59800 p (t-test) 0.83 0.64 0.48 Min 1370 63300 1370 190 1370 49200 Max 520000 371000 520000 506000 520000 297000 n (Samp) 122 52 122 55 122 25 n (Patient) 88 52 88 55 88 25 sCr only Median 181000 199000 181000 210000 181000 179000 Average 184000 200000 184000 227000 184000 180000 Stdev 70200 62800 70200 97800 70200 54800 p (t-test) 0.38 0.030 0.87 Min 190 118000 190 129000 190 108000 Max 520000 316000 520000 506000 520000 280000 n (Samp) 291 16 291 14 291 9 n (Patient) 164 16 164 14 164 9 UO only Median 180000 182000 180000 180000 180000 172000 Average 189000 187000 189000 176000 189000 178000 Stdev 81700 69000 81700 63300 81700 59400 p (t-test) 0.92 0.32 0.57 Min 1080 63300 1080 190 1080 49200 Max 520000 371000 520000 337000 520000 297000 n (Samp) 124 43 124 57 124 23 n (Patient) 81 43 81 57 81 23 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.53 0.58 0.50 0.48 0.64 0.48 0.48 0.49 0.49 SE 0.048 0.077 0.051 0.047 0.082 0.047 0.064 0.099 0.066 p 0.59 0.30 0.98 0.72 0.098 0.63 0.71 0.90 0.84 nCohort 1 122 291 124 122 291 124 122 291 124 nCohort 2 52 16 43 55 14 57 25 9 23 Cutoff 1 152000 160000 141000 151000 175000 144000 147000 144000 147000 Sens 1 71% 75% 72% 71% 71% 70% 72% 78% 74% Spec 1 32% 37% 23% 32% 46% 25% 27% 26% 28% Cutoff 2 134000 125000 130000 133000 164000 123000 125000 115000 125000 Sens 2 81% 81% 81% 80% 86% 81% 80% 89% 83% Spec 2 20% 17% 19% 20% 39% 12% 14% 14% 15% Cutoff 3 106000 118000 105000 107000 133000 107000 115000 107000 115000 Sens 3 90% 94% 91% 91% 93% 91% 92% 100%  91% Spec 3  9% 14%  9% 10% 21% 10% 11% 11% 12% Cutoff 4 212000 207000 209000 212000 207000 209000 212000 207000 209000 Sens 4 31% 44% 33% 29% 50% 25% 32% 22% 35% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 227000 227000 228000 227000 227000 228000 227000 227000 228000 Sens 5 25% 38% 21% 25% 43% 23% 32% 22% 35% Spec 5 80% 80% 81% 80% 80% 81% 80% 80% 81% Cutoff 6 262000 262000 257000 262000 262000 257000 262000 262000 257000 Sens 6 13% 12% 14%  7% 14%  9%  8% 11%  9% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 0.87 0.48 0.66 0.75 2.1 1.1 0.32 1.0 0.21 p Value 0.76 0.41 0.41 0.53 0.41 0.77 0.11 1.0 0.058 95% CI of 0.34 0.085 0.24 0.30 0.37 0.47 0.078 0.14 0.041 OR Quart 2 2.2 2.7 1.8 1.9 12 2.8 1.3 7.3 1.1 OR Quart 3 0.89 0.99 0.86 0.75 1.0 0.74 0.85 1.5 0.85 p Value 0.81 0.98 0.75 0.53 1.0 0.52 0.77 0.65 0.77 95% CI of 0.35 0.24 0.33 0.30 0.14 0.29 0.27 0.25 0.27 OR Quart 3 2.3 4.1 2.2 1.9 7.3 1.9 2.6 9.4 2.6 OR Quart 4 1.2 1.5 0.86 1.1 3.1 1.4 0.88 1.0 0.72 p Value 0.70 0.53 0.75 0.76 0.17 0.46 0.82 1.0 0.59 95% CI of 0.48 0.41 0.33 0.48 0.61 0.58 0.28 0.14 0.22 OR Quart 4 2.9 5.6 2.2 2.7 16 3.3 2.7 7.3 2.3 Tumor necrosis factor ligand superfamily member 10 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.0228 0.0313 0.0228 0.0239 0.0228 0.0313 Average 8.36 2.81 8.36 4.03 8.36 6.36 Stdev 43.2 6.38 43.2 9.01 43.2 14.2 p (t-test) 0.40 0.54 0.85 Min 0.0162 0.0162 0.0162 0.0162 0.0162 0.0162 Max 292 31.9 292 35.0 292 44.8 n (Samp) 95 43 95 39 95 17 n (Patient) 69 43 69 39 69 17 sCr only Median 0.0313 0.0315 0.0313 0.0228 0.0313 4.67 Average 6.23 2.84 6.23 5.61 6.23 13.8 Stdev 29.8 9.15 29.8 11.2 29.8 18.7 p (t-test) 0.70 0.93 0.45 Min 0.0162 0.0162 0.0162 0.0162 0.0162 0.0162 Max 292 31.9 292 35.0 292 44.8 n (Samp) 223 12 223 18 223 9 n (Patient) 138 12 138 18 138 9 UO only Median 0.0313 0.0313 0.0313 0.0313 0.0313 0.0313 Average 9.24 2.29 9.24 4.53 9.24 0.671 Stdev 42.8 4.74 42.8 16.5 42.8 2.10 p (t-test) 0.32 0.51 0.46 Min 0.0162 0.0162 0.0162 0.0162 0.0162 0.0162 Max 292 16.7 292 98.4 292 7.88 n (Samp) 98 38 98 39 98 14 n (Patient) 67 38 67 39 67 14 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.51 0.49 0.47 0.52 0.44 0.47 0.65 0.70 0.49 SE 0.053 0.086 0.056 0.055 0.073 0.055 0.077 0.099 0.083 p 0.82 0.90 0.54 0.69 0.41 0.55 0.051 0.043 0.94 nCohort 1 95 223 98 95 223 98 95 223 98 nCohort 2 43 12 38 39 18 39 17 9 14 Cutoff 1 0.0162 0.0205 0.0197 0.0197 0.0162 0.0197 0.0247 0.0313 0.0269 Sens 1 81% 75% 71% 79% 83% 77% 88% 78% 79% Spec 1 15% 24% 21% 25% 13% 21% 53% 54% 47% Cutoff 2 0.0162 0.0162 0.0162 0.0162 0.0162 0.0162 0.0247 0.0205 0.0197 Sens 2 81% 83% 82% 85% 83% 82% 88% 89% 86% Spec 2 15% 13% 10% 15% 13% 10% 53% 24% 21% Cutoff 3 0 0 0 0 0 0 0.0162 0 0.0162 Sens 3 100%  100%  100%  100%  100%  100%  94% 100%  93% Spec 3  0%  0%  0%  0%  0%  0% 15%  0% 10% Cutoff 4 0.0317 0.171 0.0363 0.0317 0.171 0.0363 0.0317 0.171 0.0363 Sens 4 30% 25% 26% 28% 22% 26% 41% 56% 14% Spec 4 73% 70% 71% 73% 70% 71% 73% 70% 71% Cutoff 5 0.328 3.32 1.53 0.328 3.32 1.53 0.328 3.32 1.53 Sens 5 30%  8% 21% 28% 22% 21% 35% 56%  7% Spec 5 80% 80% 81% 80% 80% 81% 80% 80% 81% Cutoff 6 4.64 10.8 7.32 4.64 10.8 7.32 4.64 10.8 7.32 Sens 6 19%  8% 16% 21% 22% 10% 29% 33%  7% Spec 6 91% 90% 91% 91% 90% 91% 91% 90% 91% OR Quart 2 0.54 2.1 0.85 1.1 0.75 0.90 1.6 1.0 2.2 p Value 0.26 0.41 0.78 0.85 0.71 0.85 0.64 1.0 0.40 95% CI of 0.19 0.36 0.28 0.38 0.16 0.31 0.24 0.061 0.36 OR Quart 2 1.6 12 2.6 3.2 3.5 2.6 10 16 13 OR Quart 3 0.76 1.5 0.85 1.0 1.3 0.77 2.8 2.0 3.5 p Value 0.60 0.65 0.78 1.0 0.71 0.63 0.24 0.57 0.14 95% CI of 0.28 0.25 0.28 0.34 0.33 0.26 0.50 0.18 0.65 OR Quart 3 2.1 9.5 2.6 3.0 5.1 2.3 16 23 19 OR Quart 4 1.1 1.6 1.7 1.3 1.6 1.4 4.3 5.4 1.0 p Value 0.87 0.64 0.30 0.65 0.49 0.55 0.086 0.13 1.0 95% CI of 0.41 0.25 0.61 0.45 0.42 0.49 0.81 0.61 0.13 OR Quart 4 2.9 9.7 4.8 3.6 5.9 3.8 23 48 7.6 Myeloid differentiation primary response protein MyD88 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.000368 0.000245 0.000368 0.000368 0.000368 0.000457 Average 0.00255 0.00199 0.00255 0.000350 0.00255 0.00458 Stdev 0.0181 0.00785 0.0181 9.42E−5 0.0181 0.0138 p (t-test) 0.86 0.46 0.72 Min 0.000224 0.000224 0.000224 0.000224 0.000224 0.000224 Max 0.171 0.0441 0.171 0.000457 0.171 0.0463 n (Samp) 90 33 90 37 90 11 n (Patient) 63 33 63 37 63 11 sCr only Median 0.000368 0.000245 0.000368 0.000224 0.000368 0.000457 Average 0.00184 0.000291 0.00184 0.000301 0.00184 0.000368 Stdev 0.0129 8.43E−5 0.0129 0.000121 0.0129 0.000122 p (t-test) 0.72 0.77 0.80 Min 0.000126 0.000224 0.000126 0.000224 0.000126 0.000224 Max 0.171 0.000457 0.171 0.000457 0.171 0.000457 n (Samp) 202 9 202 6 202 5 n (Patient) 121 9 121 6 121 5 UO only Median 0.000332 0.000245 0.000332 0.000368 0.000332 0.000457 Average 0.00450 0.00230 0.00450 0.000348 0.00450 0.00456 Stdev 0.0265 0.00850 0.0265 9.37E−5 0.0265 0.0138 p (t-test) 0.67 0.34 0.99 Min 0.000224 0.000224 0.000224 0.000224 0.000224 0.000224 Max 0.194 0.0441 0.194 0.000457 0.194 0.0463 n (Samp) 94 28 94 38 94 11 n (Patient) 58 28 58 38 58 11 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.42 0.40 0.45 0.53 0.36 0.55 0.71 0.60 0.68 SE 0.059 0.10 0.063 0.057 0.12 0.056 0.091 0.14 0.093 p 0.17 0.35 0.44 0.63 0.26 0.34 0.022 0.47 0.053 nCohort 1 90 202 94 90 202 94 90 202 94 nCohort 2 33 9 28 37 6 38 11 5 11 Cutoff 1 0 0.000224 0 0.000224 0.000126 0.000224 0.000296 0.000224 0.000296 Sens 1 100%  78% 100%  81% 100%  84% 91% 80% 82% Spec 1  0% 24%  0% 21%  0% 24% 43% 24% 50% Cutoff 2 0 0.000126 0 0.000224 0.000126 0.000224 0.000296 0.000224 0.000296 Sens 2 100%  100%  100%  81% 100%  84% 91% 80% 82% Spec 2  0%  0%  0% 21%  0% 24% 43% 24% 50% Cutoff 3 0 0.000126 0 0 0.000126 0 0.000296 0.000126 0.000224 Sens 3 100%  100%  100%  100%  100%  100%  91% 100%  91% Spec 3  0%  0%  0%  0%  0%  0% 43%  0% 24% Cutoff 4 0.000368 0.000368 0.000368 0.000368 0.000368 0.000368 0.000368 0.000368 0.000368 Sens 4 18% 11% 18% 32% 33% 32% 64% 60% 55% Spec 4 71% 72% 72% 71% 72% 72% 71% 72% 72% Cutoff 5 0.000457 0.000457 0.000457 0.000457 0.000457 0.000457 0.000457 0.000457 0.000457 Sens 5  6%  0%  7%  0%  0%  0%  9%  0%  9% Spec 5 96% 96% 95% 96% 96% 95% 96% 96% 95% Cutoff 6 0.000457 0.000457 0.000457 0.000457 0.000457 0.000457 0.000457 0.000457 0.000457 Sens 6  6%  0%  7%  0%  0%  0%  9%  0%  9% Spec 6 96% 96% 95% 96% 96% 95% 96% 96% 95% OR Quart 2 1.5 0 1.9 1.5 0 1.2 0 0.98 1.0 p Value 0.52 na 0.32 0.46 na 0.78 na 0.99 1.0 95% CI of 0.42 na 0.54 0.51 na 0.39 na 0.060 0.059 OR Quart 2 5.4 na 6.6 4.5 na 3.5 na 16 17 OR Quart 3 2.5 6.6 1.8 1.3 0 1.6 11 0.98 3.3 p Value 0.14 0.085 0.35 0.63 na 0.42 0.029 0.99 0.32 95% CI of 0.73 0.77 0.52 0.44 na 0.53 1.3 0.060 0.32 OR Quart 3 8.4 57 6.3 3.9 na 4.6 99 16 34 OR Quart 4 3.0 2.1 1.6 0.96 2.1 1.4 2.0 2.0 7.1 p Value 0.075 0.55 0.48 0.94 0.41 0.58 0.58 0.58 0.079 95% CI of 0.90 0.18 0.44 0.31 0.36 0.46 0.17 0.18 0.80 OR Quart 4 10 24 5.7 3.0 12 4.0 24 23 64

TABLE 6 Comparison of marker levels in EDTA samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0 or R) and in EDTA samples collected from subjects at 0, 24 hours, and 48 hours prior to reaching stage I or F in Cohort 2. Heat shock 70 kDa protein 1 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 934 840 934 928 Average 1680 957 1680 967 Stdev 2210 694 2210 860 p (t-test) 0.33 0.44 Min 0.288 16.7 0.288 0.288 Max 10700 2280 10700 1970 n (Samp) 113 9 113 6 n (Patient) 92 9 92 6 UO only Median 934 840 934 336 Average 1650 957 1650 817 Stdev 2190 694 2190 870 p (t-test) 0.35 0.40 Min 0.288 16.7 0.288 0.288 Max 10700 2280 10700 1970 n (Samp) 99 9 99 5 n (Patient) 77 9 77 5 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.46 nd 0.47 0.44 nd 0.39 SE 0.10 nd 0.10 0.12 nd 0.14 p 0.73 nd 0.75 0.66 nd 0.44 nCohort 1 113 nd 99 113 nd 99 nCohort 2 9 nd 9 6 nd 5 Cutoff 1 705 nd 664 252 nd 252 Sens 1 78% nd 78% 83% nd 80% Spec 1 44% nd 44% 23% nd 25% Cutoff 2 114 nd 114 252 nd 252 Sens 2 89% nd 89% 83% nd 80% Spec 2 15% nd 16% 23% nd 25% Cutoff 3 4.58 nd 4.58 0 nd 0 Sens 3 100%  nd 100%  100%  nd 100%  Spec 3  6% nd  7%  0% nd  0% Cutoff 4 1620 nd 1610 1620 nd 1610 Sens 4 11% nd 11% 33% nd 20% Spec 4 71% nd 71% 71% nd 71% Cutoff 5 2930 nd 2930 2930 nd 2930 Sens 5  0% nd  0%  0% nd  0% Spec 5 81% nd 81% 81% nd 81% Cutoff 6 3970 nd 4330 3970 nd 4330 Sens 6  0% nd  0%  0% nd  0% Spec 6 90% nd 91% 90% nd 91% OR Quart 2 3.3 nd 3.2 2.1 nd >2.2 p Value 0.31 nd 0.32 0.56 nd <0.54 95% CI of 0.33 nd 0.32 0.18 nd >0.18 OR Quart 2 34 nd 33 24 nd na OR Quart 3 3.2 nd 3.2 1.0 nd >2.2 p Value 0.32 nd 0.32 1.0 nd <0.54 95% CI of 0.32 nd 0.32 0.060 nd >0.18 OR Quart 3 33 nd 33 17 nd na OR Quart 4 2.1 nd 2.1 2.1 nd >1.0 p Value 0.54 nd 0.56 0.54 nd <0.98 95% CI of 0.18 nd 0.18 0.18 nd >0.062 OR Quart 4 25 nd 24 25 nd na Insulin-like growth factor 1 receptor 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.0484 0.0572 0.0484 0.0619 0.0484 0.0426 Average 0.346 2.67 0.346 0.938 0.346 1.38 Stdev 2.22 6.87 2.22 3.58 2.22 5.00 p (t-test) 0.017 0.32 0.13 Min 9.84E−5 0.0144 9.84E−5 0.000211 9.84E−5 0.000211 Max 21.0 18.2 21.0 14.8 21.0 19.4 n (Samp) 183 7 183 17 183 15 n (Patient) 122 7 122 17 122 15 sCr only Median 0.0498 0.0888 0.0498 7.45 0.0498 0.0596 Average 0.300 6.12 0.300 7.45 0.300 4.90 Stdev 2.01 10.5 2.01 10.4 2.01 9.70 p (t-test) 1.2E−5 3.9E−6 9.6E−5 Min 9.84E−5 0.0144 9.84E−5 0.0742 9.84E−5 0.0214 Max 21.0 18.2 21.0 14.8 21.0 19.4 n (Samp) 222 3 222 2 222 4 n (Patient) 145 3 145 2 145 4 UO only Median 0.0498 0.0572 0.0498 0.0572 0.0498 0.0449 Average 0.393 0.0892 0.393 0.0668 0.393 0.102 Stdev 2.37 0.0767 2.37 0.0525 2.37 0.149 p (t-test) 0.80 0.57 0.67 Min 0.000208 0.0390 0.000208 0.000211 0.000208 0.000211 Max 21.0 0.204 21.0 0.192 21.0 0.543 n (Samp) 159 4 159 17 159 12 n (Patient) 102 4 102 17 102 12 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.65 0.65 0.62 0.60 0.85 0.54 0.54 0.59 0.52 SE 0.11 0.17 0.15 0.075 0.17 0.075 0.079 0.15 0.088 p 0.19 0.38 0.42 0.17 0.038 0.61 0.58 0.55 0.80 nCohort 1 183 222 159 183 222 159 183 222 159 nCohort 2 7 3 4 17 2 17 15 4 12 Cutoff 1 0.0556 0.0137 0.0556 0.0407 0.0729 0.0373 0.0219 0.0390 0.0219 Sens 1 71% 100%  75% 71% 100%  71% 73% 75% 75% Spec 1 60% 15% 57% 44% 72% 40% 25% 41% 23% Cutoff 2 0.0373 0.0137 0.0373 0.0297 0.0729 0.0253 0.0212 0.0212 0.0212 Sens 2 86% 100%  100%  82% 100%  82% 93% 100%  92% Spec 2 42% 15% 40% 33% 72% 25% 21% 20% 18% Cutoff 3 0.0137 0.0137 0.0373 0.00949 0.0729 0.00497 0.0212 0.0212 0.0212 Sens 3 100%  100%  100%  94% 100%  94% 93% 100%  92% Spec 3 15% 15% 40% 11% 72%  9% 21% 20% 18% Cutoff 4 0.0692 0.0699 0.0729 0.0692 0.0699 0.0729 0.0692 0.0699 0.0729 Sens 4 43% 67% 25% 41% 100%  35% 40% 50% 42% Spec 4 71% 71% 70% 71% 71% 70% 71% 71% 70% Cutoff 5 0.0839 0.0839 0.0839 0.0839 0.0839 0.0839 0.0839 0.0839 0.0839 Sens 5 43% 67% 25% 29% 50% 29% 33% 25% 33% Spec 5 80% 80% 81% 80% 80% 81% 80% 80% 81% Cutoff 6 0.129 0.133 0.134 0.129 0.133 0.134 0.129 0.133 0.134 Sens 6 29% 33% 25% 18% 50% 12% 20% 25% 17% Spec 6 90% 90% 91% 90% 90% 91% 90% 90% 91% OR Quart 2 0.98 0 >1.0 2.1 >0 1.4 1.2 0.98 1.3 p Value 0.99 na <1.0 0.41 <na 0.69 0.75 0.99 0.72 95% CI of 0.059 na >0.060 0.36 >na 0.29 0.32 0.060 0.28 OR Quart 2 16 na na 12 na 6.5 5.0 16 6.4 OR Quart 3 2.0 0 >2.1 2.7 >1.0 1.8 0.23 1.0 0.31 p Value 0.56 na <0.56 0.26 <0.99 0.46 0.20 1.0 0.32 95% CI of 0.18 na >0.18 0.49 >0.062 0.39 0.025 0.061 0.031 OR Quart 3 23 na na 14 na 7.8 2.2 16 3.1 OR Quart 4 3.1 2.0 >1.0 3.3 >1.0 1.8 1.2 0.98 1.3 p Value 0.34 0.58 <1.0 0.16 <0.99 0.46 0.75 0.99 0.72 95% CI of 0.31 0.18 >0.060 0.63 >0.062 0.39 0.32 0.060 0.28 OR Quart 4 31 23 na 17 na 7.8 5.0 16 6.4 Neural cell adhesion molecule 1 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 184000 178000 184000 185000 184000 156000 Average 189000 187000 189000 191000 189000 158000 Stdev 70300 63200 70300 93000 70300 51300 p (t-test) 0.90 0.91 0.060 Min 791 93200 791 190 791 49200 Max 520000 316000 520000 506000 520000 280000 n (Samp) 285 16 285 28 285 19 n (Patient) 163 16 163 28 163 19 sCr only Median 181000 243000 181000 232000 181000 175000 Average 184000 236000 184000 295000 184000 190000 Stdev 68800 73300 68800 135000 68800 53400 p (t-test) 0.14 5.0E−4 0.86 Min 190 140000 190 160000 190 140000 Max 520000 316000 520000 506000 520000 280000 n (Samp) 356 4 356 5 356 5 n (Patient) 197 4 197 5 197 5 UO only Median 183000 172000 183000 177000 183000 156000 Average 188000 168000 188000 169000 188000 155000 Stdev 72400 51800 72400 65000 72400 47600 p (t-test) 0.32 0.19 0.058 Min 791 93200 791 190 791 49200 Max 520000 282000 520000 331000 520000 230000 n (Samp) 261 13 261 26 261 17 n (Patient) 143 13 143 26 143 17 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.49 0.73 0.41 0.48 0.79 0.43 0.36 0.51 0.36 SE 0.075 0.15 0.085 0.058 0.12 0.061 0.070 0.13 0.074 p 0.92 0.12 0.29 0.79 0.015 0.25 0.041 0.91 0.052 nCohort 1 285 356 261 285 356 261 285 356 261 nCohort 2 16 4 13 28 5 26 19 5 17 Cutoff 1 152000 230000 133000 158000 230000 130000 139000 166000 144000 Sens 1 75% 75% 77% 71% 80% 73% 74% 80% 71% Spec 1 30% 81% 21% 32% 81% 19% 21% 41% 26% Cutoff 2 133000 140000 121000 125000 230000 121000 107000 166000 107000 Sens 2 81% 100%  85% 82% 80% 81% 84% 80% 82% Spec 2 19% 24% 14% 14% 81% 14%  8% 41%  9% Cutoff 3 95600 140000 95600 91800 160000 91800 91800 140000 91800 Sens 3 94% 100%  92% 93% 100%  92% 95% 100%  94% Spec 3  6% 24%  6%  5% 37%  5%  5% 24%  5% Cutoff 4 214000 207000 214000 214000 207000 214000 214000 207000 214000 Sens 4 25% 75%  8% 29% 80% 19% 11% 20% 12% Spec 4 70% 71% 70% 70% 71% 70% 70% 71% 70% Cutoff 5 233000 228000 233000 233000 228000 233000 233000 228000 233000 Sens 5 19% 75%  8% 14% 80% 12%  5% 20%  0% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 266000 262000 265000 266000 262000 265000 266000 262000 265000 Sens 6 12% 25%  8% 11% 40%  4%  5% 20%  0% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR 0.75 0 3.1 1.0 >1.0 2.1 2.1 2.0 1.5 Quart 2 p Value 0.71 na 0.33 0.98 <0.99 0.24 0.41 0.57 0.64 95% CI of 0.16 na 0.32 0.34 >0.062 0.61 0.37 0.18 0.25 OR 3.5 na 31 3.0 na 7.4 12 23 9.5 Quart 2 OR 1.3 0 5.3 0.86 >0 1.3 3.8 1.0 3.8 Quart 3 p Value 0.72 na 0.13 0.79 <na 0.73 0.11 1.0 0.11 95% CI of 0.33 na 0.60 0.27 >na 0.33 0.75 0.062 0.76 OR 5.0 na 47 2.7 na 4.9 19 16 19 Quart 3 OR 1.0 3.1 4.2 1.2 >4.1 2.5 3.2 0.99 2.7 Quart 4 p Value 0.98 0.34 0.20 0.77 <0.21 0.15 0.17 0.99 0.25 95% CI of 0.24 0.31 0.46 0.40 >0.45 0.72 0.62 0.061 0.50 OR 4.2 30 39 3.4 na 8.4 16 16 14 Quart 4 Myeloid differentiation primary response protein MyD88 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.000368 0.000245 0.000368 0.000368 0.000368 0.000368 Average 0.00279 0.000236 0.00279 0.000326 0.00279 0.000351 Stdev 0.0186 1.14E−5 0.0186 9.54E−5 0.0186 0.000109 p (t-test) 0.68 0.59 0.70 Min 0.000126 0.000224 0.000126 0.000224 0.000126 0.000224 Max 0.194 0.000245 0.194 0.000457 0.194 0.000457 n (Samp) 203 9 203 17 203 9 n (Patient) 120 9 120 17 120 9 sCr only Median nd nd nd nd 0.000368 0.000340 Average nd nd nd nd 0.00235 0.000340 Stdev nd nd nd nd 0.0169 0.000165 p (t-test) nd nd nd nd 0.87 Min nd nd nd nd 0.000126 0.000224 Max nd nd nd nd 0.194 0.000457 n (Samp) nd nd nd nd 246 2 n (Patient) nd nd nd nd 142 2 UO only Median 0.000368 0.000245 0.000368 0.000368 0.000368 0.000307 Average 0.00296 0.000236 0.00296 0.000326 0.00296 0.000337 Stdev 0.0193 1.14E−5 0.0193 9.54E−5 0.0193 0.000108 p (t-test) 0.67 0.57 0.70 Min 0.000126 0.000224 0.000126 0.000224 0.000126 0.000224 Max 0.194 0.000245 0.194 0.000457 0.194 0.000457 n (Samp) 189 9 189 17 189 8 n (Patient) 106 9 106 17 106 8 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.24 nd 0.25 0.47 nd 0.48 0.56 0.48 0.54 SE 0.095 nd 0.096 0.074 nd 0.074 0.10 0.21 0.11 p 0.0060 nd 0.0098 0.73 nd 0.82 0.54 0.94 0.74 nCohort 1 203 nd 189 203 nd 189 203 246 189 nCohort 2 9 nd 9 17 nd 17 9 2 8 Cutoff 1 0.000126 nd 0.000126 0.000224 nd 0.000224 0.000224 0.000126 0.000224 Sens 1 100%  nd 100%  76% nd 76% 89% 100%  88% Spec 1  0% nd  1% 23% nd 24% 23%  0% 24% Cutoff 2 0.000126 nd 0.000126 0.000126 nd 0.000126 0.000224 0.000126 0.000224 Sens 2 100%  nd 100%  100%  nd 100%  89% 100%  88% Spec 2  0% nd  1%  0% nd  1% 23%  0% 24% Cutoff 3 0.000126 nd 0.000126 0.000126 nd 0.000126 0.000126 0.000126 0.000126 Sens 3 100%  nd 100%  100%  nd 100%  100%  100%  100%  Spec 3  0% nd  1%  0% nd  1%  0% 0%  1% Cutoff 4 0.000368 nd 0.000368 0.000368 nd 0.000368 0.000368 0.000368 0.000368 Sens 4  0% nd  0% 24% nd 24% 44% 50% 38% Spec 4 71% nd 71% 71% nd 71% 71% 73% 71% Cutoff 5 0.000457 nd 0.000457 0.000457 nd 0.000457 0.000457 0.000457 0.000457 Sens 5  0% nd  0%  0% nd  0%  0%  0%  0% Spec 5 96% nd 95% 96% nd 95% 96% 96% 95% Cutoff 6 0.000457 nd 0.000457 0.000457 nd 0.000457 0.000457 0.000457 0.000457 Sens 6  0% nd  0%  0% nd  0%  0%  0%  0% Spec 6 96% nd 95% 96% nd 95% 96% 96% 95% OR Quart 2 >0 nd >0 0.32 nd 1.3 4.2 0 3.1 p Value <na nd <na 0.33 nd 0.70 0.20 na 0.33 95% CI of >na nd >na 0.032 nd 0.33 0.46 na 0.31 OR Quart 2 na nd na 3.2 nd 5.2 39 na 31 OR Quart 3 >5.5 nd >5.6 3.4 nd 1.0 0 0 1.0 p Value <0.12 nd <0.12 0.080 nd 1.0 na na 1.0 95% CI of >0.62 nd >0.63 0.87 nd 0.24 na na 0.061 OR Quart 3 na nd na 13 nd 4.2 na na 16 OR Quart 4 >4.3 nd >4.4 1.4 nd 1.0 4.2 1.0 3.1 p Value <0.20 nd <0.19 0.70 nd 0.98 0.20 1.0 0.34 95% CI of >0.47 nd >0.48 0.29 nd 0.24 0.46 0.061 0.31 OR Quart 4 na nd na 6.4 nd 4.3 39 16 31

TABLE 7 Comparison of marker levels in EDTA samples collected within 12 hours of reaching stage R from Cohort 1 (patients that reached, but did not progress beyond, RIFLE stage R) and from Cohort 2 (patients that reached RIFLE stage I or F). Insulin-like growth factor 1 receptor sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 0.0447 0.0717 nd nd 0.0478 0.0804 Average 0.574 0.103 nd nd 0.707 0.0835 Stdev 3.27 0.114 nd nd 3.71 0.0515 p (t-test) 0.62 nd nd 0.62 Min 0.000208 0.0214 nd nd 0.000208 0.0214 Max 20.5 0.432 nd nd 21.0 0.192 n (Samp) 39 12 nd nd 32 9 n (Patient) 39 12 nd nd 32 9 At Enrollment sCr or UO sCr only UO only AUC 0.66 nd 0.71 SE 0.095 nd 0.11 p 0.088 nd 0.047 nCohort 1 39 nd 32 nCohort 2 12 nd 9 Cutoff 1 0.0331 nd 0.0545 Sens 1 75% nd 78% Spec 1 31% nd 59% Cutoff 2 0.0292 nd 0.0214 Sens 2 83% nd 89% Spec 2 28% nd 25% Cutoff 3 0.0214 nd 0.0179 Sens 3 92% nd 100%  Spec 3 26% nd 19% Cutoff 4 0.0608 nd 0.0608 Sens 4 58% nd 67% Spec 4 72% nd 72% Cutoff 5 0.0692 nd 0.0668 Sens 5 50% nd 67% Spec 5 82% nd 81% Cutoff 6 0.0945 nd 0.0839 Sens 6 33% nd 44% Spec 6 92% nd 91% OR Quart 2 0.91 nd 0 p Value 0.93 nd na 95% CI of 0.11 nd na OR Quart 2 7.7 nd na OR Quart 3 0.91 nd 1.0 p Value 0.93 nd 1.0 95% CI of 0.11 nd 0.11 OR Quart 3 7.7 nd 8.9 OR Quart 4 4.3 nd 3.3 p Value 0.13 nd 0.23 95% CI of 0.66 nd 0.47 OR Quart 4 28 nd 23 Tumor necrosis factor ligand superfamily member 10 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 0.0315 0.0228 nd nd 0.0315 0.0228 Average 6.86 1.36 nd nd 2.72 1.74 Stdev 27.8 5.65 nd nd 5.07 6.41 p (t-test) 0.41 nd nd 0.58 Min 0.0162 0.0162 nd nd 0.0162 0.0162 Max 172 24.0 nd nd 16.7 24.0 n (Samp) 38 18 nd nd 32 14 n (Patient) 38 18 nd nd 32 14 At Enrollment sCr or UO sCr only UO only AUC 0.28 nd 0.29 SE 0.078 nd 0.088 p 0.0054 nd 0.017 nCohort 1 38 nd 32 nCohort 2 18 nd 14 Cutoff 1 0.0197 nd 0.0197 Sens 1 72% nd 71% Spec 1 18% nd 16% Cutoff 2 0 nd 0 Sens 2 100%  nd 100%  Spec 2  0% nd  0% Cutoff 3 0 nd 0 Sens 3 100%  nd 100%  Spec 3  0% nd  0% Cutoff 4 0.601 nd 0.444 Sens 4  6% nd  7% Spec 4 71% nd 72% Cutoff 5 6.98 nd 6.98 Sens 5  6% nd  7% Spec 5 82% nd 81% Cutoff 6 13.4 nd 10.8 Sens 6  6% nd  7% Spec 6 92% nd 91% OR Quart 2 2.2 nd 0.50 p Value 0.55 nd 0.59 95% CI of 0.17 nd 0.039 OR Quart 2 27 nd 6.4 OR Quart 3 17 nd 5.0 p Value 0.015 nd 0.096 95% CI of 1.8 nd 0.75 OR Quart 3 170 nd 33 OR Quart 4 13 nd 4.2 p Value 0.028 nd 0.15 95% CI of 1.3 nd 0.61 OR Quart 4 130 nd 29

TABLE 8 Comparison of the maximum marker levels in EDTA samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0) and the maximum values in EDTA samples collected from subjects between enrollment and 0, 24 hours, and 48 hours prior to reaching stage F in Cohort 2. Heat shock 70 kDa protein 1 0 hr prior to AKI stage 24 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 618 2280 618 2280 Average 1400 2650 1400 2650 Stdev 2030 2030 2030 2030 p (t-test) 0.30 0.30 Min 0.288 840 0.288 840 Max 10000 4840 10000 4840 n (Samp) 53 3 53 3 n (Patient) 53 3 53 3 UO only Median 641 1560 641 1560 Average 1410 1560 1410 1560 Stdev 1930 1020 1930 1020 p (t-test) 0.92 0.92 Min 0.288 840 0.288 840 Max 10000 2280 10000 2280 n (Samp) 44 2 44 2 n (Patient) 44 2 44 2 0 hr prior to AKI stage 24 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.77 nd 0.66 0.77 nd 0.66 SE 0.16 nd 0.22 0.16 nd 0.22 p 0.093 nd 0.46 0.093 nd 0.46 nCohort 1 53 nd 44 53 nd 44 nCohort 2 3 nd 2 3 nd 2 Cutoff 1 837 nd 837 837 nd 837 Sens 1 100%  nd 100%  100%  nd 100%  Spec 1 57% nd 55% 57% nd 55% Cutoff 2 837 nd 837 837 nd 837 Sens 2 100%  nd 100%  100%  nd 100%  Spec 2 57% nd 55% 57% nd 55% Cutoff 3 837 nd 837 837 nd 837 Sens 3 100%  nd 100%  100%  nd 100%  Spec 3 57% nd 55% 57% nd 55% Cutoff 4 1370 nd 1370 1370 nd 1370 Sens 4 67% nd 50% 67% nd 50% Spec 4 72% nd 70% 72% nd 70% Cutoff 5 2700 nd 2860 2700 nd 2860 Sens 5 33% nd  0% 33% nd  0% Spec 5 81% nd 82% 81% nd 82% Cutoff 6 3540 nd 3630 3540 nd 3630 Sens 6 33% nd  0% 33% nd  0% Spec 6 91% nd 91% 91% nd 91% OR Quart 2 >0 nd >0 >0 nd >0 p Value <na nd <na <na nd <na 95% CI of >na nd >na >na nd >na OR Quart 2 na nd na na nd na OR Quart 3 >1.1 nd >1.1 >1.1 nd >1.1 p Value <0.96 nd <0.95 <0.96 nd <0.95 95% CI of >0.061 nd >0.060 >0.061 nd >0.060 OR Quart 3 na nd na na nd na OR Quart 4 >2.3 nd >1.0 >2.3 nd >1.0 p Value <0.51 nd <1.0 <0.51 nd <1.0 95% CI of >0.19 nd >0.055 >0.19 nd >0.055 OR Quart 4 na nd na na nd na Neural cell adhesion molecule 1 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 184000 172000 184000 172000 184000 167000 Average 188000 180000 188000 177000 188000 165000 Stdev 79000 49600 79000 44400 79000 20800 p (t-test) 0.78 0.69 0.57 Min 1370 111000 1370 111000 1370 140000 Max 520000 256000 520000 245000 520000 187000 n (Samp) 88 8 88 8 88 4 n (Patient) 88 8 88 8 88 4 sCr only Median 181000 177000 181000 177000 181000 167000 Average 187000 188000 187000 181000 187000 165000 Stdev 75100 49800 75100 38000 75100 23700 p (t-test) 0.98 0.88 0.61 Min 190 140000 190 140000 190 140000 Max 520000 256000 520000 230000 520000 187000 n (Samp) 164 4 164 4 164 3 n (Patient) 164 4 164 4 164 3 UO only Median 180000 162000 180000 162000 180000 158000 Average 187000 166000 187000 166000 187000 158000 Stdev 85300 45100 85300 45100 85300 18300 p (t-test) 0.56 0.56 0.56 Min 1080 111000 1080 111000 1080 140000 Max 520000 245000 520000 245000 520000 176000 n (Samp) 81 6 81 6 81 3 n (Patient) 81 6 81 6 81 3 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.47 0.50 0.41 0.47 0.48 0.41 0.39 0.38 0.36 SE 0.11 0.15 0.13 0.11 0.15 0.13 0.15 0.17 0.18 p 0.80 0.99 0.47 0.75 0.92 0.47 0.48 0.49 0.43 nCohort 1 88 164 81 88 164 81 88 164 81 nCohort 2 8 4 6 8 4 6 4 3 3 Cutoff 1 158000 165000 139000 158000 165000 139000 158000 139000 139000 Sens 1 75% 75% 83% 75% 75% 83% 75% 100%  100%  Spec 1 36% 40% 25% 36% 40% 25% 36% 22% 25% Cutoff 2 139000 139000 139000 139000 139000 139000 139000 139000 139000 Sens 2 88% 100%  83% 88% 100%  83% 100%  100%  100%  Spec 2 24% 22% 25% 24% 22% 25% 24% 22% 25% Cutoff 3 107000 139000 107000 107000 139000 107000 139000 139000 139000 Sens 3 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 3 11% 22% 12% 11% 22% 12% 24% 22% 25% Cutoff 4 216000 217000 214000 216000 217000 214000 216000 217000 214000 Sens 4 25% 25% 17% 25% 25% 17%  0%  0%  0% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 227000 230000 227000 227000 230000 227000 227000 230000 227000 Sens 5 25% 25% 17% 25%  0% 17%  0%  0%  0% Spec 5 81% 80% 80% 81% 80% 80% 81% 80% 80% Cutoff 6 272000 272000 258000 272000 272000 258000 272000 272000 258000 Sens 6  0%  0%  0%  0%  0%  0%  0%  0%  0% Spec 6 91% 90% 90% 91% 90% 90% 91% 90% 90% OR Quart 2 0.48 1.0 0 0.48 1.0 0 >1.0 >1.0 >0 p Value 0.56 1.0 na 0.56 1.0 na <0.98 <0.99 <na 95% CI of 0.040 0.060 na 0.040 0.060 na >0.062 >0.062 >na OR Quart 2 5.7 17 na 5.7 17 na na na na OR Quart 3 1.6 1.0 4.7 1.6 1.0 4.7 >2.2 >1.0 >2.2 p Value 0.64 1.0 0.19 0.64 1.0 0.19 <0.53 <0.99 <0.53 95% CI of 0.24 0.060 0.48 0.24 0.060 0.48 >0.18 >0.062 >0.19 OR Quart 3 10 17 46 10 17 46 na na na OR Quart 4 1.0 1.0 1.0 1.0 1.0 1.0 >1.0 >1.0 >1.0 p Value 1.0 1.0 0.97 1.0 1.0 0.97 <0.98 <0.97 <0.97 95% CI of 0.13 0.060 0.061 0.13 0.060 0.061 >0.062 >0.064 >0.061 OR Quart 4 7.7 17 18 7.7 17 18 na na na Tumor necrosis factor ligand superfamily member 10 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.0228 0.0271 0.0228 0.0271 0.0228 0.0228 Average 11.3 3.14 11.3 3.14 11.3 2.39 Stdev 50.4 7.16 50.4 7.16 50.4 5.88 p (t-test) 0.58 0.58 0.64 Min 0.0162 0.0162 0.0162 0.0162 0.0162 0.0162 Max 292 20.9 292 20.9 292 15.7 n (Samp) 69 12 69 12 69 7 n (Patient) 69 12 69 12 69 7 sCr only Median 0.0313 0.0228 0.0313 0.0228 0.0313 0.0228 Average 9.00 2.64 9.00 2.64 9.00 5.25 Stdev 37.6 6.40 37.6 6.40 37.6 9.06 p (t-test) 0.68 0.68 0.86 Min 0.0162 0.0162 0.0162 0.0162 0.0162 0.0162 Max 292 15.7 292 15.7 292 15.7 n (Samp) 138 6 138 6 138 3 n (Patient) 138 6 138 6 138 3 UO only Median 0.0313 0.0271 0.0313 0.0271 0.0313 0.0228 Average 13.0 2.74 13.0 2.74 13.0 0.173 Stdev 51.4 7.33 51.4 7.33 51.4 0.367 p (t-test) 0.58 0.58 0.55 Min 0.0162 0.0162 0.0162 0.0162 0.0162 0.0162 Max 292 20.9 292 20.9 292 0.921 n (Samp) 67 8 67 8 67 6 n (Patient) 67 8 67 8 67 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.50 0.37 0.44 0.50 0.37 0.44 0.48 0.41 0.35 SE 0.091 0.12 0.11 0.091 0.12 0.11 0.12 0.18 0.13 p 0.96 0.30 0.59 0.96 0.30 0.59 0.85 0.60 0.25 nCohort 1 69 138 67 69 138 67 69 138 67 nCohort 2 12 6 8 12 6 8 7 3 6 Cutoff 1 0.0197 0.0205 0.0197 0.0197 0.0205 0.0197 0.0197 0 0.0197 Sens 1 92% 83% 88% 92% 83% 88% 86% 100%  83% Spec 1 17% 14% 12% 17% 14% 12% 17%  0% 12% Cutoff 2 0.0197 0.0205 0.0197 0.0197 0.0205 0.0197 0.0197 0 0.0197 Sens 2 92% 83% 88% 92% 83% 88% 86% 100%  83% Spec 2 17% 14% 12% 17% 14% 12% 17%  0% 12% Cutoff 3 0.0197 0 0 0.0197 0 0 0 0 0 Sens 3 92% 100%  100%  92% 100%  100%  100%  100%  100%  Spec 3 17%  0%  0% 17%  0%  0%  0%  0%  0% Cutoff 4 0.0392 0.921 0.0591 0.0392 0.921 0.0591 0.0392 0.921 0.0591 Sens 4 25% 17% 25% 25% 17% 25% 29% 33% 17% Spec 4 71% 70% 70% 71% 70% 70% 71% 70% 70% Cutoff 5 2.12 3.82 3.20 2.12 3.82 3.20 2.12 3.82 3.20 Sens 5 17% 17% 12% 17% 17% 12% 14% 33%  0% Spec 5 81% 80% 81% 81% 80% 81% 81% 80% 81% Cutoff 6 5.31 15.7 23.0 5.31 15.7 23.0 5.31 15.7 23.0 Sens 6 17%  0%  0% 17%  0%  0% 14%  0%  0% Spec 6 91% 91% 91% 91% 91% 91% 91% 91% 91% OR Quart 2 6.3 0 2.1 6.3 0 2.1 0.47 0 >2.4 p Value 0.11 na 0.55 0.11 na 0.55 0.55 na <0.50 95% CI of 0.67 na 0.18 0.67 na 0.18 0.039 na >0.20 OR Quart 2 60 na 26 60 na 26 5.7 na na OR Quart 3 3.4 4.4 1.0 3.4 4.4 1.0 1.6 1.0 >0 p Value 0.31 0.20 1.0 0.31 0.20 1.0 0.63 0.98 <na 95% CI of 0.32 0.46 0.058 0.32 0.46 0.058 0.23 0.062 >na OR Quart 3 35 41 17 35 41 17 11 17 na OR Quart 4 3.2 1.0 5.1 3.2 1.0 5.1 0.47 1.0 >5.4 p Value 0.34 1.0 0.16 0.34 1.0 0.16 0.55 0.98 <0.15 95% CI of 0.30 0.060 0.52 0.30 0.060 0.52 0.039 0.062 >0.55 OR Quart 4 33 17 51 33 17 51 5.7 17 na

TABLE 9 Comparison of marker levels in urine samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0, R, or I) and in urine samples collected from Cohort 2 (subjects who progress to RIFLE stage F) at 0, 24 hours, and 48 hours prior to the subject reaching RIFLE stage I. Stromelysin-1:Metalloproteinase inhibitor 2 complex 24 hr prior to AKI stage Cohort 1 Cohort 2 sCr or UO Median 0.487 0.487 Average 177 40.1 Stdev 1320 100 p (t-test) 0.79 Min 0.237 0.487 Max 13900 267 n (Samp) 113 7 n (Patient) 87 7 sCr only Median 0.487 10.9 Average 171 181 Stdev 1290 303 p (t-test) 0.99 Min 0.237 0.487 Max 13900 530 n (Samp) 118 3 n (Patient) 91 3 UO only Median 0.237 0.487 Average 190 53.8 Stdev 1430 119 p (t-test) 0.83 Min 0.237 0.487 Max 13900 267 n (Samp) 96 5 n (Patient) 74 5 24 hr prior to AKI stage sCr or UO sCr only UO only AUC 0.71 0.81 0.73 SE 0.11 0.15 0.13 p 0.063 0.046 0.081 nCohort 1 113 118 96 nCohort 2 7 3 5 Cutoff 1 0.237 0.237 0.237 Sens 1 100%  100%  100%  Spec 1 45% 43% 52% Cutoff 2 0.237 0.237 0.237 Sens 2 100%  100%  100%  Spec 2 45% 43% 52% Cutoff 3 0.237 0.237 0.237 Sens 3 100%  100%  100%  Spec 3 45% 43% 52% Cutoff 4 0.487 0.487 0.487 Sens 4 29% 67% 20% Spec 4 82% 82% 82% Cutoff 5 0.487 0.487 0.487 Sens 5 29% 67% 20% Spec 5 82% 82% 82% Cutoff 6 123 154 118 Sens 6 14% 33% 20% Spec 6 90% 91% 91% OR Quart 2 >6.0 >1.0 >0 p Value <0.11 <0.98 <na 95% CI of >0.66 >0.062 >na OR Quart 2 na na na OR Quart 3 >0 >0 >4.8 p Value <na <na <0.18 95% CI of >na >na >0.49 OR Quart 3 na na na OR Quart 4 >2.1 >2.1 >1.0 p Value <0.54 <0.56 <1.0 95% CI of >0.18 >0.18 >0.059 OR Quart 4 na na na Heat shock 70 kDa protein 1 24 hr prior to AKI stage Cohort 1 Cohort 2 sCr or UO Median 277 1420 Average 581 2850 Stdev 1100 4410 p (t-test) 2.0E−4 Min 0.297 250 Max 7800 11800 n (Samp) 111 6 n (Patient) 86 6 sCr only Median 289 1510 Average 686 1440 Stdev 1500 318 p (t-test) 0.39 Min 0.297 1090 Max 11800 1710 n (Samp) 115 3 n (Patient) 89 3 UO only Median 267 934 Average 617 3480 Stdev 1170 5560 p (t-test) 3.5E−4 Min 0.297 250 Max 7800 11800 n (Samp) 96 4 n (Patient) 74 4 24 hr prior to AKI stage sCr or UO sCr only UO only AUC 0.83 0.92 0.77 SE 0.10 0.11 0.14 p 0.0018 1.9E−4 0.055 nCohort 1 111 115 96 nCohort 2 6 3 4 Cutoff 1 529 1040 529 Sens 1 83% 100%  75% Spec 1 70% 89% 70% Cutoff 2 529 1040 246 Sens 2 83% 100%  100%  Spec 2 70% 89% 49% Cutoff 3 246 1040 246 Sens 3 100%  100%  100%  Spec 3 48% 89% 49% Cutoff 4 529 596 574 Sens 4 83% 100%  50% Spec 4 70% 70% 71% Cutoff 5 770 782 782 Sens 5 67% 100%  50% Spec 5 80% 80% 80% Cutoff 6 1040 1320 1340 Sens 6 67% 67% 25% Spec 6 90% 91% 91% OR Quart 2 >1.0 >0 >1.0 p Value <0.98 <na <0.98 95% CI of >0.062 >na >0.062 OR Quart 2 na na na OR Quart 3 >1.0 >0 >1.0 p Value <0.98 <na <0.98 95% CI of >0.062 >na >0.062 OR Quart 3 na na na OR Quart 4 >4.5 >3.2 >2.2 p Value <0.19 <0.32 <0.54 95% CI of >0.47 >0.32 >0.18 OR Quart 4 na na na Insulin-like growth factor 1 receptor 24 hr prior to AKI stage Cohort 1 Cohort 2 sCr or UO Median 0.0103 0.0103 Average 0.0227 0.0647 Stdev 0.0655 0.132 p (t-test) 0.13 Min 0.000123 0.00862 Max 0.679 0.365 n (Samp) 112 7 n (Patient) 88 7 sCr only Median 0.0103 0.0197 Average 0.0261 0.0160 Stdev 0.0718 0.00637 p (t-test) 0.81 Min 0.000123 0.00862 Max 0.679 0.0197 n (Samp) 117 3 n (Patient) 92 3 UO only Median 0.0103 0.0103 Average 0.0239 0.0849 Stdev 0.0705 0.157 p (t-test) 0.083 Min 0.000123 0.0103 Max 0.679 0.365 n (Samp) 96 5 n (Patient) 76 5 24 hr prior to AKI stage sCr or UO sCr only UO only AUC 0.61 0.57 0.65 SE 0.12 0.17 0.14 p 0.34 0.71 0.28 nCohort 1 112 117 96 nCohort 2 7 3 5 Cutoff 1 0.00862 0.00573 0.00862 Sens 1 86% 100%  100%  Spec 1 41% 32% 44% Cutoff 2 0.00862 0.00573 0.00862 Sens 2 86% 100%  100%  Spec 2 41% 32% 44% Cutoff 3 0.00573 0.00573 0.00862 Sens 3 100%  100%  100%  Spec 3 33% 32% 44% Cutoff 4 0.0197 0.0211 0.0211 Sens 4 29%  0% 40% Spec 4 71% 71% 72% Cutoff 5 0.0292 0.0292 0.0292 Sens 5 14%  0% 20% Spec 5 82% 81% 82% Cutoff 6 0.0423 0.0423 0.0423 Sens 6 14%  0% 20% Spec 6 92% 91% 92% OR Quart 2 >4.5 >1.0 >1.0 p Value <0.19 <0.98 <0.98 95% CI of >0.47 >0.062 >0.062 OR Quart 2 na na na OR Quart 3 >1.0 >2.1 >2.2 p Value <1.0 <0.54 <0.54 95% CI of >0.060 >0.18 >0.18 OR Quart 3 na na na OR Quart 4 >2.1 >0 >2.1 p Value <0.56 <na <0.56 95% CI of >0.18 >na >0.18 OR Quart 4 na na na Interstitial collagenase:Metalloproteinase inhibitor 2 complex 24 hr prior to AKI stage Cohort 1 Cohort 2 sCr or UO Median 0.233 6.17 Average 152 50.7 Stdev 1510 110 p (t-test) 0.86 Min 0.228 0.228 Max 16000 297 n (Samp) 113 7 n (Patient) 87 7 sCr only Median 0.233 6.97 Average 149 12.2 Stdev 1470 15.3 p (t-test) 0.87 Min 0.228 0.233 Max 16000 29.5 n (Samp) 118 3 n (Patient) 91 3 UO only Median 0.233 6.17 Average 173 69.6 Stdev 1630 129 p (t-test) 0.89 Min 0.228 0.228 Max 16000 297 n (Samp) 96 5 n (Patient) 74 5 24 hr prior to AKI stage sCr or UO sCr only UO only AUC 0.66 0.79 0.62 SE 0.12 0.16 0.14 p 0.17 0.072 0.37 nCohort 1 113 118 96 nCohort 2 7 3 5 Cutoff 1 0.228 0.228 0 Sens 1 71% 100%  100%  Spec 1 38% 39%  0% Cutoff 2 0 0.228 0 Sens 2 100%  100%  100%  Spec 2  0% 39%  0% Cutoff 3 0 0.228 0 Sens 3 100%  100%  100%  Spec 3  0% 39%  0% Cutoff 4 0.233 0.233 0.233 Sens 4 57% 67% 60% Spec 4 80% 79% 79% Cutoff 5 1.26 1.35 1.26 Sens 5 57% 67% 60% Spec 5 81% 81% 80% Cutoff 6 14.2 18.5 10.7 Sens 6 29% 33% 40% Spec 6 90% 92% 91% OR Quart 2 >2.1 >0 0 p Value <0.54 <na na 95% CI of >0.18 >na na OR Quart 2 na na na OR Quart 3 >1.0 >1.0 0 p Value <0.98 <0.98 na 95% CI of >0.062 >0.062 na OR Quart 3 na na na OR Quart 4 >4.6 >2.1 1.5 p Value <0.18 <0.56 0.67 95% CI of >0.48 >0.18 0.23 OR Quart 4 na na 9.8 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex 24 hr prior to AKI stage Cohort 1 Cohort 2 sCr or UO Median 29.2 295 Average 793 2740 Stdev 2550 5880 p (t-test) 0.081 Min 1.15 1.15 Max 16000 16000 n (Samp) 108 7 n (Patient) 86 7 sCr only Median 30.3 527 Average 926 447 Stdev 2880 245 p (t-test) 0.77 Min 1.15 171 Max 16000 642 n (Samp) 113 3 n (Patient) 90 3 UO only Median 28.1 295 Average 868 3670 Stdev 2710 6930 p (t-test) 0.044 Min 1.15 1.15 Max 16000 16000 n (Samp) 95 5 n (Patient) 76 5 24 hr prior to AKI stage sCr or UO sCr only UO only AUC 0.70 0.74 0.67 SE 0.11 0.17 0.14 p 0.081 0.16 0.21 nCohort 1 108 113 95 nCohort 2 7 3 5 Cutoff 1 234 164 234 Sens 1 71% 100%  80% Spec 1 71% 65% 69% Cutoff 2 164 164 234 Sens 2 86% 100%  80% Spec 2 67% 65% 69% Cutoff 3 0 164 0 Sens 3 100%  100%  100%  Spec 3  0% 65%  0% Cutoff 4 227 365 365 Sens 4 71% 67% 40% Spec 4 70% 71% 71% Cutoff 5 595 656 595 Sens 5 43%  0% 40% Spec 5 81% 81% 80% Cutoff 6 1700 1780 1700 Sens 6 29%  0% 40% Spec 6 91% 90% 91% OR Quart 2 0 >0 0 p Value na <na na 95% CI of na >na na OR Quart 2 na na na OR Quart 3 3.1 >1.0 2.1 p Value 0.34 <0.98 0.56 95% CI of 0.30 >0.062 0.18 OR Quart 3 32 na 25 OR Quart 4 3.1 >2.1 2.1 p Value 0.34 <0.54 0.56 95% CI of 0.30 >0.18 0.18 OR Quart 4 32 na 25 Neural cell adhesion molecule 1 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 2720 3990 2720 2690 2720 2100 Average 3340 4390 3340 6270 3340 2870 Stdev 2880 3520 2880 11900 2880 2900 p (t-test) 0.093 5.4E−5 0.60 Min 0.234 171 0.234 375 0.234 138 Max 48400 15000 48400 55700 48400 9700 n (Samp) 1261 22 1261 20 1261 10 n (Patient) 450 22 450 20 450 10 sCr only Median 2780 2260 2780 3970 2780 3900 Average 3450 2670 3450 3650 3450 3740 Stdev 3260 2170 3260 2070 3260 2410 p (t-test) 0.50 0.90 0.86 Min 0.234 171 0.234 1090 0.234 963 Max 55700 6800 55700 5590 55700 6210 n (Samp) 1325 8 1325 4 1325 4 n (Patient) 465 8 465 4 465 4 UO only Median 2840 4560 2840 4560 2840 3280 Average 3410 6830 3410 8190 3410 3570 Stdev 2840 6750 2840 12900 2840 3190 p (t-test) 1.4E−5 3.0E−10 0.88 Min 0.234 416 0.234 375 0.234 346 Max 48400 26600 48400 55700 48400 9700 n (Samp) 1116 14 1116 19 1116 7 n (Patient) 364 14 364 19 364 7 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.59 0.42 0.70 0.55 0.58 0.62 0.40 0.57 0.48 SE 0.064 0.11 0.079 0.067 0.15 0.069 0.095 0.15 0.11 p 0.16 0.44 0.010 0.45 0.59 0.084 0.32 0.65 0.88 nCohort 1 1261 1325 1116 1261 1325 1116 1261 1325 1116 nCohort 2 22 8 14 20 4 19 10 4 7 Cutoff 1 2200 1340 3860 2030 2870 2080 1180 2560 1650 Sens 1 73% 75% 71% 70% 75% 74% 70% 75% 71% Spec 1 39% 19% 67% 35% 52% 34% 16% 46% 24% Cutoff 2 1340 623 2310 1740 1090 1740 957 957 1180 Sens 2 82% 88% 86% 80% 100%  84% 80% 100%  86% Spec 2 20%  5% 39% 28% 14% 26% 11% 10% 14% Cutoff 3 623 169 1490 1110 1090 1110 341 957 325 Sens 3 91% 100%  93% 90% 100%  95% 90% 100%  100%  Spec 3  5%  0% 21% 15% 14% 13%  1% 10%  1% Cutoff 4 3940 4040 4060 3940 4040 4060 3940 4040 4060 Sens 4 55% 12% 57% 45% 50% 58% 20% 50% 29% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 4850 4930 4910 4850 4930 4910 4850 4930 4910 Sens 5 41% 12% 43% 35% 50% 42% 20% 50% 29% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 6440 6520 6470 6440 6520 6470 6440 6520 6470 Sens 6 23% 12% 29% 20%  0% 32% 10%  0% 14% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 0.33 2.0 0.50 1.5 0 1.7 1.0 1.0 1.0 p Value 0.17 0.57 0.57 0.53 na 0.48 1.0 1.0 1.0 95% CI of 0.066 0.18 0.045 0.42 na 0.40 0.14 0.062 0.14 OR Quart 2 1.6 22 5.5 5.4 na 7.1 7.1 16 7.1 OR Quart 3 0.83 2.0 2.0 0.50 1.0 0.33 1.0 0 0 p Value 0.76 0.57 0.42 0.42 1.0 0.34 1.0 na na 95% CI of 0.25 0.18 0.37 0.090 0.062 0.034 0.14 na na OR Quart 3 2.7 22 11 2.7 16 3.2 7.1 na na OR Quart 4 1.5 3.0 3.6 2.0 2.0 3.4 2.0 2.0 1.5 p Value 0.44 0.34 0.12 0.26 0.57 0.065 0.42 0.57 0.65 95% CI of 0.53 0.31 0.73 0.60 0.18 0.93 0.37 0.18 0.25 OR Quart 4 4.3 29 17 6.8 22 13 11 22 9.1 Tumor necrosis factor ligand superfamily member 10 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.0285 0.0287 0.0285 0.0387 0.0285 0.0287 Average 2.55 7.89 2.55 9.52 2.55 0.125 Stdev 9.75 24.9 9.75 30.0 9.75 0.289 p (t-test) 0.017 0.0029 0.46 Min 0.0110 0.0139 0.0110 0.0110 0.0110 0.0205 Max 159 113 159 134 159 0.894 n (Samp) 1234 21 1234 20 1234 9 n (Patient) 456 21 456 20 456 9 sCr only Median 0.0285 0.0243 0.0285 1.57 0.0285 0.0287 Average 2.78 1.22 2.78 1.66 2.78 0.0300 Stdev 10.9 3.38 10.9 1.89 10.9 0.00805 p (t-test) 0.69 0.84 0.62 Min 0.0110 0.0139 0.0110 0.0227 0.0110 0.0217 Max 159 9.58 159 3.47 159 0.0410 n (Samp) 1294 8 1294 4 1294 4 n (Patient) 471 8 471 4 471 4 UO only Median 0.0285 0.0311 0.0285 0.0410 0.0285 0.0363 Average 2.57 13.5 2.57 15.4 2.57 0.153 Stdev 9.97 27.1 9.97 38.8 9.97 0.327 p (t-test) 8.5E−5 6.1E−7 0.52 Min 0.0110 0.0139 0.0110 0.0110 0.0110 0.0205 Max 159 79.6 159 134 159 0.894 n (Samp) 1092 14 1092 19 1092 7 n (Patient) 372 14 372 19 372 7 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.57 0.45 0.59 0.61 0.58 0.61 0.46 0.49 0.48 SE 0.066 0.11 0.081 0.068 0.15 0.069 0.099 0.15 0.11 p 0.30 0.61 0.25 0.12 0.59 0.098 0.72 0.95 0.85 nCohort 1 1234 1294 1092 1234 1294 1092 1234 1294 1092 nCohort 2 21 8 14 20 4 19 9 4 7 Cutoff 1 0.0247 0.0239 0.0285 0.0247 0.0239 0.0247 0.0217 0.0285 0.0237 Sens 1 76% 88% 71% 70% 75% 74% 78% 75% 71% Spec 1 41% 33% 51% 41% 33% 40% 22% 52% 28% Cutoff 2 0.0239 0.0239 0.0247 0.0217 0.0217 0.0205 0.0205 0.0205 0.0217 Sens 2 81% 88% 86% 80% 100%  89% 89% 100%  86% Spec 2 37% 33% 40% 22% 22% 17% 19% 18% 21% Cutoff 3 0.0239 0.0110 0.0110 0.0205 0.0217 0.0162 0.0162 0.0205 0.0162 Sens 3 90% 100%  100%  90% 100%  95% 100%  100%  100%  Spec 3 34%  3%  3% 19% 22% 14% 15% 18% 14% Cutoff 4 0.0439 0.0410 0.0439 0.0439 0.0410 0.0439 0.0439 0.0410 0.0439 Sens 4 24% 12% 29% 45% 50% 47% 11%  0% 14% Spec 4 74% 70% 74% 74% 70% 74% 74% 70% 74% Cutoff 5 0.0597 0.0597 0.0597 0.0597 0.0597 0.0597 0.0597 0.0597 0.0597 Sens 5 24% 12% 29% 45% 50% 47% 11%  0% 14% Spec 5 80% 80% 81% 80% 80% 81% 80% 80% 81% Cutoff 6 5.80 5.86 5.80 5.80 5.86 5.80 5.80 5.86 5.80 Sens 6 19% 12% 29% 15%  0% 16%  0%  0%  0% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 3.0 1.0 1.00 0.39 1.00 0.20 4.0 >3.0 3.0 p Value 0.18 1.00 1.00 0.27 1.00 0.14 0.21 <0.34 0.34 95% CI of 0.61 0.062 0.14 0.076 0.062 0.023 0.45 >0.31 0.31 OR Quart 2 15 16 7.1 2.1 16 1.7 36 na 29 OR Quart 3 4.1 5.1 3.0 0.80 0 0.79 2.0 >0 1.0 p Value 0.078 0.14 0.18 0.74 na 0.73 0.57 <na 1.0 95% CI of 0.86 0.59 0.61 0.21 na 0.21 0.18 >na 0.062 OR Quart 3 19 44 15 3.0 na 3.0 22 na 16 OR Quart 4 2.5 1.0 2.0 1.8 2.0 1.8 2.0 >1.0 2.0 p Value 0.27 1.00 0.42 0.29 0.57 0.29 0.57 <1.00 0.57 95% CI of 0.48 0.062 0.36 0.60 0.18 0.60 0.18 >0.063 0.18 OR Quart 4 13 16 11 5.5 22 5.5 22 na 22 Myeloid differentiation primary response protein MyD88 0 hr prior to 24 hr prior to AKI stage AKI stage sCr or UO Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 0.000533 0.000146 0.000533 0.000165 Average 0.0162 0.000146 0.0162 0.00319 Stdev 0.0567 2.76E−5 0.0567 0.00825 p (t-test) 0.69 0.52 Min 0.000126 0.000126 0.000126 0.000165 Max 0.671 0.000165 0.671 0.0236 n (Samp) 247 2 247 8 n (Patient) 141 2 141 8 24 hr prior to AKI stage Cohort 1 Cohort 2 sCr only Median 0.000533 0.000165 Average 0.0159 0.000288 Stdev 0.0562 0.000213 p (t-test) 0.63 Min 0.000126 0.000165 Max 0.671 0.000533 n (Samp) 252 3 n (Patient) 145 3 UO only Median 0.000533 0.000165 Average 0.0141 0.000239 Stdev 0.0390 0.000165 p (t-test) 0.43 Min 0.000126 0.000165 Max 0.371 0.000533 n (Samp) 233 5 n (Patient) 128 5 0 hr prior to AKI stage 24 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.13 nd nd 0.38 0.33 0.28 SE 0.16 nd nd 0.11 0.17 0.13 p 0.027 nd nd 0.25 0.33 0.093 nCohort 1 247 nd nd 247 252 233 nCohort 2 2 nd nd 8 3 5 Cutoff 1 0 nd nd 0.000126 0.000126 0.000126 Sens 1 100%  nd nd 100%  100%  100%  Spec 1  0% nd nd 11% 10% 12% Cutoff 2 0 nd nd 0.000126 0.000126 0.000126 Sens 2 100%  nd nd 100%  100%  100%  Spec 2  0% nd nd 11% 10% 12% Cutoff 3 0 nd nd 0.000126 0.000126 0.000126 Sens 3 100%  nd nd 100%  100%  100%  Spec 3  0% nd nd 11% 10% 12% Cutoff 4 0.00247 nd nd 0.00247 0.00237 0.00616 Sens 4  0% nd nd 12%  0%  0% Spec 4 70% nd nd 70% 70% 71% Cutoff 5 0.0184 nd nd 0.0184 0.0184 0.0190 Sens 5  0% nd nd 12%  0%  0% Spec 5 80% nd nd 80% 81% 80% Cutoff 6 0.0393 nd nd 0.0393 0.0387 0.0387 Sens 6  0% nd nd  0%  0%  0% Spec 6 90% nd nd 90% 90% 90% OR Quart 2 >0 nd nd 2.0 >0 >1.0 p Value <na nd nd 0.57 <na <0.98 95% CI of >na nd nd 0.18 >na >0.063 OR Quart 2 na nd nd 23 na na OR Quart 3 >0 nd nd 5.3 >3.1 >0 p Value <na nd nd 0.13 <0.33 <na 95% CI of >na nd nd 0.61 >0.32 >na OR Quart 3 na nd nd 47 na na OR Quart 4 >2.1 nd nd 0 >0 >4.4 p Value <0.55 nd nd na <na <0.19 95% CI of >0.19 nd nd na >na >0.47 OR Quart 4 na nd nd na na na

TABLE 10 Comparison of marker levels in EDTA samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0, R, or I) and in EDTA samples collected from Cohort 2 (subjects who progress to RIFLE stage F) at 0, 24 hours, and 48 hours prior to the subject reaching RIFLE stage I. Heat shock 70 kDa protein 1 24 hr prior to AKI stage Cohort 1 Cohort 2 sCr or UO Median 905 1560 Average 1560 1560 Stdev 2100 1020 p(t-test) 1.00 Min 0.288 840 Max 10700 2280 n (Samp) 129 2 n (Patient) 106 2 UO only Median 929 1560 Average 1550 1560 Stdev 2080 1020 p(t-test) 1.00 Min 0.288 840 Max 10700 2280 n (Samp) 113 2 n (Patient) 90 2 24 hr prior to AKI stage sCr or UO sCr only UO only AUC 0.64 nd 0.64 SE 0.21 nd 0.21 p 0.51 nd 0.52 nCohort 1 129 nd 113 nCohort 2 2 nd 2 Cutoff 1 837 nd 837 Sens 1 100%  nd 100%  Spec 1 49% nd 49% Cutoff 2 837 nd 837 Sens 2 100%  nd 100%  Spec 2 49% nd 49% Cutoff 3 837 nd 837 Sens 3 100%  nd 100%  Spec 3 49% nd 49% Cutoff 4 1560 nd 1560 Sens 4 50% nd 50% Spec 4 71% nd 71% Cutoff 5 2550 nd 2550 Sens 5  0% nd  0% Spec 5 81% nd 81% Cutoff 6 3630 nd 3540 Sens 6  0% nd  0% Spec 6 91% nd 90% OR Quart 2 >1.0 nd >1.0 p Value <1.0 nd <1.0 95% CI of >0.060 nd >0.060 OR Quart2 na nd na OR Quart 3 >0 nd >0 p Value <na  nd <na  95% CI of >na  nd >na  OR Quart3 na nd na OR Quart 4 >1.0 nd >1.0 p Value <1.0 nd <1.0 95% CI of >0.060 nd >0.060 OR Quart4 na nd na Insulin-like growth factor 1 receptor 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.0484 0.0490 0.0484 0.0644 0.0484 0.0214 Average 0.521 0.0490 0.521 0.0732 0.521 0.0337 Stdev 2.80 0.0562 2.80 0.0681 2.80 0.0410 p(t-test) 0.81 0.75 0.76 Min 9.84E−5 0.00927 9.84E−5 0.000211 9.84E−5 0.000211 Max 21.0 0.0888 21.0 0.164 21.0 0.0795 n (Samp) 229 2 229 4 229 3 n (Patient) 148 2 148 4 148 3 UO only Median nd nd 0.0520 0.0319 0.0520 0.0108 Average nd nd 0.336 0.0570 0.336 0.0108 Stdev nd nd 2.14 0.0752 2.14 0.0150 p(t-test) nd nd 0.80 0.83 Min nd nd 0.000172 0.000211 0.000172 0.000211 Max nd nd 21.0 0.164 21.0 0.0214 n (Samp) nd nd 196 4 196 2 n (Patient) nd nd 124 4 124 2 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.46 nd nd 0.56 nd 0.39 0.33 nd 0.11 SE 0.21 nd nd 0.15 nd 0.15 0.17 nd 0.15 p 0.83 nd nd 0.71 nd 0.47 0.32 nd 0.010 nCohort 1 229 nd nd 229 nd 196 229 nd 196 nCohort 2 2 nd nd 4 nd 4 3 nd 2 Cutoff 1 0.00767 nd nd 0.0535 nd 0.00497 0.000208 nd 0.000208 Sens 1 100%  nd nd 75% nd 75% 100%  nd 100%  Spec 1 10% nd nd 55% nd  9% 3% nd 3% Cutoff 2 0.00767 nd nd 0.000208 nd 0.000208 0.000208 nd 0.000208 Sens 2 100%  nd nd 100%  nd 100%  100%  nd 100%  Spec 2 10% nd nd  3% nd  3% 3% nd 3% Cutoff 3 0.00767 nd nd 0.000208 nd 0.000208 0.000208 nd 0.000208 Sens 3 100%  nd nd 100%  nd 100% 100%  nd 100%  Spec 3 10% nd nd  3% nd  3% 3% nd 3% Cutoff 4 0.0699 nd nd 0.0699 nd 0.0769 0.0699 nd 0.0769 Sens 4 50% nd nd 50% nd 25% 33%  nd 0% Spec 4 70% nd nd 70% nd 70% 70%  nd 70%  Cutoff 5 0.0888 nd nd 0.0888 nd 0.0888 0.0888 nd 0.0888 Sens 5  0% nd nd 25% nd 25% 0% nd 0% Spec 5 81% nd nd 81% nd 81% 81%  nd 81%  Cutoff 6 0.135 nd nd 0.135 nd 0.135 0.135 nd 0.135 Sens 6  0% nd nd 25% nd 25% 0% nd 0% Spec 6 90% nd nd 90% nd 90% 90%  nd 90%  OR Quart 2 0 nd nd 0 nd 1.0 >1.0 nd >0 p Value na nd nd na nd 1.0 <0.99 nd <na 95% CI of na nd nd na nd 0.061 >0.062 nd >na OR Quart2 na nd nd na nd 16 na nd  na OR Quart 3 0 nd nd 2.0 nd 0 >0 nd >0 p Value na nd nd 0.57 nd na <na   nd <na 95% CI of na nd nd 0.18 nd na >na  nd >na OR Quart3 na nd nd 23 nd na na nd  na OR Quart 4 1.0 nd nd 0.98 nd 2.0 >2.1 nd >2.1 p Value 0.99 nd nd 0.99 nd 0.57 <0.56 nd <0.54 95% CI of 0.062 nd nd 0.060 nd 0.18 >0.18 nd >0.19 OR Quart4 17 nd nd 16 nd 23 na nd  na Neural cell adhesion molecule 1 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 181000 111000 181000 166000 181000 162000 Average 186000 154000 186000 177000 186000 163000 Stdev 72800 88700 72800 50000 72800 22700 p(t-test) 0.45 0.76 0.52 Min 190 96200 190 125000 190 140000 Max 520000 256000 520000 245000 520000 187000 n (Samp) 369 3 369 6 369 4 n (Patient) 201 3 201 6 201 4 48 hr prior to AKI stage sCr only Cohort 1 Cohort 2 Median 181000 154000 Average 186000 154000 Stdev 72400 19300 p(t-test) 0.53 Min 190 140000 Max 520000 167000 n (Samp) 376 2 n (Patient) 205 2 24 hr prior to AKI stage 48 hr prior to AKI stage UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 180000 165000 180000 162000 Average 183000 164000 183000 162000 Stdev 70100 51300 70100 20600 p(t-test) 0.55 0.68 Min 190 111000 190 147000 Max 520000 245000 520000 176000 n (Samp) 339 5 339 2 n (Patient) 178 5 178 2 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.35 nd nd 0.47 nd 0.40 0.38 0.32 0.39 SE 0.17 nd nd 0.12 nd 0.14 0.15 0.21 0.21 p 0.39 nd nd 0.79 nd 0.48 0.43 0.40 0.60 nCohort 1 369 nd nd 369 nd 339 369 376 339 nCohort 2 3 nd nd 6 nd 5 4 2 2 Cutoff 1 95600 nd nd 131000 nd 130000 147000 140000 147000 Sens 1 100%  nd nd 83% nd 80% 75% 100%  100%  Spec 1  7% nd nd 20% nd 22% 28% 24% 30% Cutoff 2 95600 nd nd 131000 nd 130000 140000 140000 147000 Sens 2 100%  nd nd 83% nd 80% 100%  100%  100%  Spec 2  7% nd nd 20% nd 22% 24% 24% 30% Cutoff 3 95600 nd nd 125000 nd 109000 140000 140000 147000 Sens 3 100%  nd nd 100%  nd 100%  100%  100%  100%  Spec 3  7% nd nd 16% nd 12% 24% 24% 30% Cutoff 4 208000 nd nd 208000 nd 207000 208000 208000 207000 Sens 4 33% nd nd 33% nd 20%  0%  0%  0% Spec 4 70% nd nd 70% nd 70% 70% 70% 70% Cutoff 5 229000 nd nd 229000 nd 228000 229000 229000 228000 Sens 5 33% nd nd 33% nd 20%  0%  0%  0% Spec 5 80% nd nd 80% nd 80% 80% 80% 80% Cutoff 6 268000 nd nd 268000 nd 262000 268000 266000 262000 Sens 6  0% nd nd  0% nd  0%  0%  0%  0% Spec 6 90% nd nd 90% nd 90% 90% 90% 90% OR Quart 2 0 nd nd 0 nd 0 >1.0 >0 >0 p Value na nd nd na nd na <0.99 <na  <na 95% CI of na nd nd na nd na >0.063 >na  >na OR Quart2 na nd nd na nd na na na  na OR Quart 3 0 nd nd 1.0 nd 2.0 >2.1 >1.0 >2.1 p Value na nd nd 1.0 nd 0.57 <0.56 <0.99 <0.55 95% CI of na nd nd 0.14 nd 0.18 >0.18 >0.062 >0.18 OR Quart3 na nd nd 7.3 nd 23 na na  na OR Quart 4 2.0 nd nd 1.0 nd 2.0 >1.0 >1.0 >0 p Value 0.57 nd nd 0.99 nd 0.57 <0.99 <0.99 <na 95% CI of 0.18 nd nd 0.14 nd 0.18 >0.063 >0.063 >na OR Quart4 23 nd nd 7.3 nd 23 na na  na Tumor necrosis factor ligand superfamily member 10 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.0313 0.0313 0.0313 0.0271 0.0313 0.0313 Average 7.00 1.03 7.00 0.615 7.00 3.95 Stdev 29.0 2.23 29.0 1.44 29.0 7.84 p(t-test) 0.65 0.59 0.83 Min 0.0162 0.0228 0.0162 0.0228 0.0162 0.0162 Max 292 5.02 292 3.56 292 15.7 n (Samp) 290 5 290 6 290 4 n (Patient) 174 5 174 6 174 4 sCr only Median 0.0313 0.0271 0.0313 0.0271 nd nd Average 6.84 0.0271 6.84 0.0271 nd nd Stdev 28.6 0.00598 28.6 0.00598 nd nd p(t-test) 0.74 0.74 nd nd Min 0.0162 0.0228 0.0162 0.0228 nd nd Max 292 0.0313 292 0.0313 nd nd n (Samp) 300 2 300 2 nd nd n (Patient) 180 2 180 2 nd nd UO only Median nd nd 0.0313 0.0228 0.0313 0.0313 Average nd nd 6.81 0.0262 6.81 0.0313 Stdev nd nd 29.7 0.00463 29.7 0 p(t-test) nd nd 0.61 0.75 Min nd nd 0.0162 0.0228 0.0162 0.0313 Max nd nd 292 0.0313 292 0.0313 n (Samp) nd nd 271 5 271 2 n (Patient) nd nd 158 5 158 2 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.48 0.40 nd 0.45 0.40 0.37 0.48 nd 0.46 SE 0.13 0.21 nd 0.12 0.21 0.14 0.15 nd 0.21 p 0.89 0.62 nd 0.67 0.62 0.35 0.89 nd 0.86 nCohort 1 290 300 nd 290 300 271 290 nd 271 nCohort 2 5 2 nd 6 2 5 4 nd 2 Cutoff 1 0.0205 0.0205 nd 0.0205 0.0205 0.0205 0.0269 nd 0.0269 Sens 1 100%  100%  nd 100%  100%  100%  75% nd 100%  Spec 1 23% 23% nd 23% 23% 23% 42% nd 41% Cutoff 2 0.0205 0.0205 nd 0.0205 0.0205 0.0205 0 nd 0.0269 Sens 2 100%  100% nd 100%  100%  100%  100%  nd 100%  Spec 2 23% 23% nd 23% 23% 23%  0% nd 41% Cutoff 3 0.0205 0.0205 nd 0.0205 0.0205 0.0205 0 nd 0.0269 Sens 3 100%  100%  nd 100%  100%  100%  100%  nd 100%  Spec 3 23% 23% nd 23% 23% 23%  0% nd 41% Cutoff 4 0.171 0.0943 nd 0.171 0.0943 0.0700 0.171 nd 0.0700 Sens 4 20%  0% nd 17%  0%  0% 25% nd  0% Spec 4 70% 70% nd 70% 70% 70% 70% nd 70% Cutoff 5 3.61 3.61 nd 3.61 3.61 3.32 3.61 nd 3.32 Sens 5 20%  0% nd  0%  0%  0% 25% nd  0% Spec 5 81% 80% nd 81% 80% 80% 81% nd 80% Cutoff 6 14.0 14.0 nd 14.0 14.0 13.4 14.0 nd 13.4 Sens 6  0%  0% nd  0%  0%  0% 25% nd  0% Spec 6 90% 90% nd 90% 90% 90% 90% nd 90% OR Quart 2 0 >0 nd 0 >0 >0 0 nd >0 p Value na <na nd na <na <na na nd <na 95% CI of na >na nd na >na >na na nd >na OR Quart2 na  na nd na  na  na na nd  na OR Quart 3 4.2 >2.1 nd 5.3 >2.1 >5.4 2.0 nd >2.1 p Value 0.21 <0.56 nd 0.13 <0.56 <0.13 0.57 nd <0.55 95% CI of 0.45 >0.18 nd 0.60 >0.18 >0.61 0.18 nd >0.19 OR Quart3 38  na nd 46  na  na 23 nd  na OR Quart 4 0 >0 nd 0 >0 >0 1.0 nd >0 p Value na <na nd na <na <na 0.99 nd <na 95% CI of na >na nd na >na >na 0.062 nd >na OR Quart4 na  na nd na  na  na 17 nd  na Myeloid differentiation primary response protein MyD88 24 hr prior to AKI stage Cohort 1 Cohort 2 sCr or UO Median 0.000368 0.000368 Average 0.00229 0.000350 Stdev 0.0167 0.000118 p(t-test) 0.84 Min 0.000126 0.000224 Max 0.194 0.000457 n (Samp) 253 3 n (Patient) 144 3 UO only Median 0.000245 0.000413 Average 0.00239 0.000413 Stdev 0.0171 6.30E−5 p(t-test) 0.87 Min 0.000126 0.000368 Max 0.194 0.000457 n (Samp) 240 2 n (Patient) 129 2 24 hr prior to AKI stage sCr or UO sCr only UO only AUC 0.53 nd 0.74 SE 0.17 nd 0.20 p 0.87 nd 0.23 nCohort 1 253 nd 240 nCohort 2 3 nd 2 Cutoff 1 0.000126 nd 0.000296 Sens 1 100%  nd 100%  Spec 1  0% nd 53% Cutoff 2 0.000126 nd 0.000296 Sens 2 100%  nd 100%  Spec 2  0% nd 53% Cutoff 3 0.000126 nd 0.000296 Sens 3 100%  nd 100%  Spec 3  0% nd 53% Cutoff 4 0.000368 nd 0.000368 Sens 4 33% nd 50% Spec 4 73% nd 74% Cutoff 5 0.000457 nd 0.000457 Sens 5  0% nd  0% Spec 5 96% nd 96% Cutoff 6 0.000457 nd 0.000457 Sens 6  0% nd  0% Spec 6 96% nd 96% OR Quart 2 1.0 nd >0 p Value 1.0 nd <na 95% CI of 0.061 nd >na OR Quart2 16 nd  na OR Quart 3 0 nd >2.1 p Value na nd <0.56 95% CI of na nd >0.18 OR Quart3 na nd  na OR Quart 4 1.0 nd >0 p Value 1.0 nd <na 95% CI of 0.061 nd >na OR Quart4 16 nd  na

TABLE 11 Comparison of marker levels in enroll urine samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0 or R within 48 hrs) and in enroll urine samples collected from Cohort 2 (subjects reaching RIFLE stage I or F within 48 hrs). Enroll samples from patients already at RIFLE stage I or F were included in Cohort 2. Stromelysin-1: Metalloproteinase inhibitor 2 complex sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 0.487 10.9 0.487 343 0.237 31.8 Average 85.9 135 82.5 295 63.8 151 Stdev 314 197 298 263 303 204 p(t-test) 0.65 0.23 0.44 Min 0.237 0.487 0.237 10.9 0.237 0.487 Max 1930 530 1930 530 1930 530 n (Samp) 49 9 55 3 41 8 n (Patient) 49 9 55 3 41 8 At Enrollment sCr or UO sCr only UO only AUC 0.79 0.90 0.82 SE 0.094 0.12 0.094 p 0.0019 7.3E−4 6.2E−4 nCohort 1 49 55 41 nCohort 2 9 3 8 Cutoff 1 0.237 3.84 0.237 Sens 1 100%  100%  100%  Spec 1 49% 82% 56% Cutoff 2 0.237 3.84 0.237 Sens 2 100%  100%  100%  Spec 2 49% 82% 56% Cutoff 3 0.237 3.84 0.237 Sens 3 100%  100%  100%  Spec 3 49% 82% 56% Cutoff 4 0.487 0.487 0.487 Sens 4 56% 100%  50% Spec 4 82% 80% 83% Cutoff 5 0.487 0.487 0.487 Sens 5 56% 100%  50% Spec 5 82% 80% 83% Cutoff 6 201 201 85.2 Sens 6 33% 67% 38% Spec 6 92% 91% 90% OR Quart 2 >2.2 >0 >1.1 p Value <0.55 <na <0.95 95% CI of >0.17 >na >0.061 OR Quart2 na  na na OR Quart 3 >2.3 >0 >4.0 p Value <0.51 <na <0.26 95% CI of >0.19 >na >0.35 OR Quart3 na  na na OR Quart 4 >7.0 >3.5 >5.3 p Value <0.097 <0.30 <0.16 95% CI of >0.71 >0.32 >0.51 OR Quart4 na  na na Heat shock 70 kDa protein 1 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 257 1300 342 1510 225 1090 Average 437 3130 690 3320 449 3360 Stdev 457 4180 1660 3510 484 4460 p(t-test) 5.2E−5 0.015 1.0E−4 Min 0.297 250 0.297 1090 0.297 250 Max 1870 11800 11800 7360 1870 11800 n (Samp) 46 8 51 3 41 7 n (Patient) 46 8 51 3 41 7 At Enrollment sCr or UO sCr only UO only AUC 0.85 0.93 0.83 SE 0.090 0.10 0.099 p 1.2E−4 4.4E−5 9.2E−4 nCohort 1 46 51 41 nCohort 2 8 3 7 Cutoff 1 755 1020 755 Sens 1 75% 100%  71% Spec 1 80% 88% 80% Cutoff 2 408 1020 408 Sens 2 88% 100%  86% Spec 2 61% 88% 61% Cutoff 3 225 1020 225 Sens 3 100%  100%  100%  Spec 3 50% 88% 51% Cutoff 4 634 660 627 Sens 4 75% 100%  71% Spec 4 72% 71% 71% Cutoff 5 755 782 755 Sens 5 75% 100%  71% Spec 5 80% 80% 80% Cutoff 6 1020 1150 1020 Sens 6 62% 67% 57% Spec 6 91% 90% 90% OR Quart 2 >1.0 >0 >1.1 p Value <1.0 <na <0.95 95% CI of >0.056 >na >0.061 OR Quart2 na  na na OR Quart 3 >2.4 >0 >2.4 p Value <0.51 <na <0.50 95% CI of >0.19 >na >0.19 OR Quart3 na  na na OR Quart 4 >7.2 >3.5 >6.0 p Value <0.093 <0.30 <0.14 95% CI of >0.72 >0.32 >0.56 OR Quart4 na  na na Insulin-like growth factor 1 receptor sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 0.0103 0.0197 0.0103 0.0197 0.0103 0.0292 Average 0.0179 0.0599 0.0245 0.0223 0.0174 0.0664 Stdev 0.0223 0.115 0.0515 0.0152 0.0233 0.122 p(t-test) 0.020 0.94 0.018 Min 0.000123 0.00132 0.000123 0.00862 0.000123 0.00132 Max 0.0976 0.365 0.365 0.0388 0.0976 0.365 n (Samp) 49 9 55 3 41 8 n (Patient) 49 9 55 3 41 8 At Enrollment sCr or UO sCr only UO only AUC 0.67 0.62 0.72 SE 0.11 0.18 0.11 p 0.11 0.49 0.039 nCohort 1 49 55 41 nCohort 2 9 3 8 Cutoff 1 0.00862 0.00454 0.00862 Sens 1 78% 100%  88% Spec 1 41% 33% 46% Cutoff 2 0.00454 0.00454 0.00862 Sens 2 89% 100%  88% Spec 2 35% 33% 46% Cutoff 3 0.000519 0.00454 0.000519 Sens 3 100%  100%  100%  Spec 3 24% 33% 29% Cutoff 4 0.0197 0.0211 0.0169 Sens 4 44% 33% 62% Spec 4 71% 71% 71% Cutoff 5 0.0296 0.0339 0.0292 Sens 5 44% 33% 50% Spec 5 82% 80% 80% Cutoff 6 0.0423 0.0436 0.0388 Sens 6 22%  0% 38% Spec 6 92% 91% 90% OR Quart 2 3.2 >1.0 >1.1 p Value 0.33 <1.0 <0.95 95% CI of 0.30 >0.057 >0.061 OR Quart2 36 na na OR Quart 3 1.0 >1.1 >4.0 p Value 1.0 <0.96 <0.26 95% CI of 0.056 >0.061 >0.35 OR Quart3 18 na na OR Quart 4 4.7 >1.0 >5.3 p Value 0.19 <1.0 <0.16 95% CI of 0.46 >0.057 >0.51 OR Quart4 49 na na 72 kDa type IV collagenase: Metalloproteinase inhibitor 2 complex sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 36.4 527 57.4 527 46.9 561 Average 345 4960 853 5570 320 5560 Stdev 585 7200 2700 9040 551 7450 p(t-test) 5.4E−5 0.016 3.4E−5 Min 1.15 1.15 1.15 171 1.15 1.15 Max 2270 16000 16000 16000 2270 16000 n (Samp) 45 9 51 3 40 8 n (Patient) 45 9 51 3 40 8 At Enrollment sCr or UO sCr only UO only AUC 0.67 0.78 0.68 SE 0.11 0.16 0.11 p 0.10 0.081 0.11 nCohort 1 45 51 40 nCohort 2 9 3 8 Cutoff 1 158 158 234 Sens 1 78% 100%  75% Spec 1 64% 61% 72% Cutoff 2 0 158 0 Sens 2 100%  100%  100%  Spec 2  0% 61%  0% Cutoff 3 0 158 0 Sens 3 100%  100%  100%  Spec 3  0% 61%  0% Cutoff 4 234 378 189 Sens 4 67% 67% 75% Spec 4 71% 71% 70% Cutoff 5 656 660 419 Sens 5 33% 33% 62% Spec 5 80% 80% 80% Cutoff 6 1380 1450 1120 Sens 6 33% 33% 38% Spec 6 91% 90% 90% OR Quart 2 0 >0 0 p Value na <na  na 95% CI of na >na  na OR Quart2 na na na OR Quart 3 1.6 >2.4 1.0 p Value 0.62 <0.51 1.0 95% CI of 0.23 >0.19 0.12 OR Quart3 12 na 8.6 OR Quart 4 2.2 >1.0 2.5 p Value 0.42 <1.0 0.35 95% CI of 0.33 >0.056 0.36 OR Quart4 15 na 17 Neural cell adhesion molecule 1 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 2440 3710 2670 4860 2490 3900 Average 3050 5520 3340 7980 3120 5680 Stdev 2340 7260 3480 8950 2140 7560 p(t-test) 5.1E−8 3.7E−7 4.7E−7 Min 6.83 138 6.83 171 173 138 Max 22000 55700 55700 31700 15500 55700 n (Samp) 380 91 448 19 297 79 n (Patient) 380 91 448 19 297 79 At Enrollment sCr or UO sCr only UO only AUC 0.65 0.68 0.64 SE 0.034 0.069 0.037 p 1.8E−5 0.011 1.2E−4 nCohort 1 380 448 297 nCohort 2 91 19 79 Cutoff 1 2670 2850 2670 Sens 1 70% 74% 71% Spec 1 54% 55% 53% Cutoff 2 2130 2200 2080 Sens 2 80% 84% 81% Spec 2 42% 42% 39% Cutoff 3 1210 1230 1110 Sens 3 90% 95% 91% Spec 3 19% 19% 14% Cutoff 4 3740 3910 3910 Sens 4 49% 53% 49% Spec 4 70% 70% 70% Cutoff 5 4550 4730 4750 Sens 5 34% 53% 34% Spec 5 80% 80% 80% Cutoff 6 5740 6280 6040 Sens 6 23% 32% 24% Spec 6 90% 90% 90% OR Quart 2 1.3 0.66 1.5 p Value 0.57 0.65 0.30 95% CI of 0.57 0.11 0.68 OR Quart2 2.7 4.0 3.5 OR Quart 3 2.5 1.3 2.6 p Value 0.013 0.71 0.017 95% CI of 1.2 0.29 1.2 OR Quart3 5.1 6.1 5.7 OR Quart 4 3.2 3.5 3.2 p Value 0.0010 0.061 0.0030 95% CI of 1.6 0.94 1.5 OR Quart4 6.5 13 6.9 Tumor necrosis factor ligand superfamily member 10 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 0.0257 0.0269 0.0257 0.0271 0.0257 0.0285 Average 2.34 4.96 2.69 6.59 2.28 5.68 Stdev 9.11 19.8 11.1 25.2 9.37 21.4 p(t-test) 0.064 0.16 0.040 Min 0.0110 0.0110 0.0110 0.0110 0.0110 0.0139 Max 83.5 134 134 113 83.5 134 n (Samp) 370 89 435 20 291 76 n (Patient) 370 89 435 20 291 76 At Enrollment sCr or UO sCr only UO only AUC 0.58 0.56 0.58 SE 0.035 0.068 0.038 p 0.015 0.37 0.024 nCohort 1 370 435 291 nCohort 2 89 20 76 Cutoff 1 0.0239 0.0239 0.0239 Sens 1 80% 70% 79% Spec 1 46% 44% 42% Cutoff 2 0.0237 0.0239 0.0237 Sens 2 85% 85% 86% Spec 2 43% 42% 40% Cutoff 3 0.0217 0.0217 0.0227 Sens 3 93% 90% 91% Spec 3 34% 29% 35% Cutoff 4 0.0439 0.0410 0.0439 Sens 4 21% 30% 22% Spec 4 74% 70% 75% Cutoff 5 0.0597 0.0597 0.0526 Sens 5 20% 30% 22% Spec 5 82% 82% 81% Cutoff 6 4.27 4.75 3.36 Sens 6 13% 10% 17% Spec 6 90% 90% 90% OR Quart 2 7.6 4.2 12 p Value 1.5E−5 0.074 1.1E−5 95% CI of 3.0 0.87 3.9 OR Quart2 19 20 35 OR Quart 3 6.4 2.0 7.2 p Value 8.4E−5 0.42 4.6E−4 95% CI of 2.5 0.36 2.4 OR Quart3 16 11 22 OR Quart 4 3.6 3.1 4.9 p Value 0.0094 0.17 0.0057 95% CI of 1.4 0.61 1.6 OR Quart4 9.3 16 15

TABLE 12 Comparison of marker levels in enroll EDTA samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0 or R within 48 hrs) and in enroll EDTA samples collected from Cohort 2 (subjects reaching RIFLE stage I or F within 48 hrs). Enroll samples from patients already at stage I or F were included in Cohort 2. Heat shock 70 kDa protein 1 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 905 1080 nd nd 949 1080 Average 1300 1080 nd nd 1200 1080 Stdev 1610 642 nd nd 1150 642 p(t-test) 0.70 nd nd 0.77 Min 4.58 261 nd nd 4.58 261 Max 9150 2280 nd nd 4430 2280 n (Samp) 46 9 nd nd 40 9 n (Patient) 46 9 nd nd 40 9 At Enrollment sCr or UO sCr only UO only AUC 0.56 nd 0.54 SE 0.11 nd 0.11 p 0.60 nd 0.73 nCohort 1 46 nd 40 nCohort 2 9 nd 9 Cutoff 1 705 nd 618 Sens 1 78% nd 78% Spec 1 48% nd 45% Cutoff 2 297 nd 297 Sens 2 89% nd 89% Spec 2 28% nd 28% Cutoff 3 252 nd 252 Sens 3 100%  nd 100%  Spec 3 24% nd 22% Cutoff 4 1370 nd 1370 Sens 4 33% nd 33% Spec 4 72% nd 70% Cutoff 5 1970 nd 1970 Sens 5 11% nd 11% Spec 5 80% nd 80% Cutoff 6 3400 nd 3300 Sens 6  0% nd  0% Spec 6 91% nd 90% OR Quart 2 3.3 nd 3.7 p Value 0.33 nd 0.29 95% CI of 0.29 nd 0.32 OR Quart2 36 nd 42 OR Quart 3 3.3 nd 3.7 p Value 0.33 nd 0.29 95% CI of 0.29 nd 0.32 OR Quart3 36 nd 42 OR Quart 4 2.0 nd 2.0 p Value 0.59 nd 0.59 95% CI of 0.16 nd 0.16 OR Quart4 25 nd 25 Insulin-like growth factor 1 receptor sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 0.0458 0.0656 0.0498 0.0283 0.0514 0.0619 Average 0.465 1.16 0.412 3.91 0.540 0.0941 Stdev 2.58 4.56 2.38 8.68 2.79 0.133 p(t-test) 0.40 0.013 0.54 Min 0.000208 0.000172 0.000172 0.00927 0.000208 0.000172 Max 20.5 19.4 20.5 19.4 20.5 0.543 n (Samp) 68 18 80 5 58 15 n (Patient) 68 18 80 5 58 15 At Enrollment sCr or UO sCr only UO only AUC 0.57 0.43 0.53 SE 0.078 0.14 0.085 p 0.39 0.62 0.70 nCohort 1 68 80 58 nCohort 2 18 5 15 Cutoff 1 0.0373 0.0134 0.0373 Sens 1 72% 80% 73% Spec 1 41% 12% 36% Cutoff 2 0.0134 0.0134 0.0258 Sens 2 83% 80% 80% Spec 2 12% 12% 26% Cutoff 3 0.000208 0.00497 0.000208 Sens 3 94% 100%  93% Spec 3  3%  9%  2% Cutoff 4 0.0668 0.0766 0.0766 Sens 4 50% 20% 40% Spec 4 71% 70% 71% Cutoff 5 0.0839 0.0839 0.0839 Sens 5 33% 20% 33% Spec 5 84% 80% 83% Cutoff 6 0.139 0.139 0.167 Sens 6 17% 20%  7% Spec 6 91% 90% 91% OR Quart 2 0.94 1.0 1.4 p Value 0.94 0.97 0.67 95% CI of 0.20 0.061 0.27 OR Quart2 4.4 18 7.5 OR Quart 3 1.0 1.0 1.0 p Value 1.0 0.97 1.0 95% CI of 0.21 0.061 0.17 OR Quart3 4.7 18 5.8 OR Quart 4 1.6 2.2 1.8 p Value 0.53 0.53 0.48 95% CI of 0.38 0.19 0.36 OR Quart4 6.7 26 8.9 Neural cell adhesion molecule 1 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 183000 162000 179000 147000 181000 162000 Average 186000 154000 180000 158000 184000 152000 Stdev  73200  64800  73400  55400  68800  65200 p(t-test) 0.034 0.56 0.036 Min   791   190   190 111000   791   190 Max 494000 331000 494000 230000 461000 331000 n (Samp)   111   28   134    4   100   26 n (Patient)   111   28   134    4   100   26 At Enrollment sCr or UO sCr only UO only AUC 0.35 0.40 0.35 SE 0.061 0.15 0.064 p 0.018 0.52 0.018 nCohort 1 111 134 100 nCohort 2 28 4 26 Cutoff 1 111000 114000 109000 Sens 1 71% 75% 73% Spec 1 13% 18% 12% Cutoff 2 93300 109000 93300 Sens 2 82% 100%  81% Spec 2  8% 15%  8% Cutoff 3 79400 109000 79400 Sens 3 93% 100%  92% Spec 3  5% 15%  5% Cutoff 4 214000 208000 214000 Sens 4 14% 25% 12% Spec 4 70% 70% 70% Cutoff 5 229000 228000 229000 Sens 5 11% 25%  8% Spec 5 80% 81% 80% Cutoff 6 268000 265000 265000 Sens 6  4%  0%  4% Spec 6 90% 90% 90% OR Quart 2 1.3 0 1.9 p Value 0.72 na 0.43 95% CI of 0.32 na 0.40 OR Quart2 5.3 na 8.6 OR Quart 3 2.3 1.0 3.2 p Value 0.21 1.0 0.11 95% CI of 0.62 0.060 0.77 OR Quart3 8.5 17 14 OR Quart 4 3.7 2.1 4.6 p Value 0.042 0.55 0.033 95% CI of 1.0 0.18 1.1 OR Quart4 13 25 19 Tumor necrosis factor ligand superfamily member 10 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 0.0247 0.0276 0.0247 0.0313 0.0313 0.0276 Average 10.2 2.74 8.59 7.70 11.1 1.20 Stdev 28.2 9.26 25.9 16.7 29.3 3.76 p(t-test) 0.19 0.93 0.12 Min 0.0162 0.0162 0.0162 0.0162 0.0162 0.0162 Max 172 44.8 172 44.8 172 15.7 n (Samp) 85 26 103 7 78 22 n (Patient) 85 26 103 7 78 22 At Enrollment sCr or UO sCr only UO only AUC 0.47 0.53 0.46 SE 0.065 0.11 0.071 p 0.70 0.82 0.60 nCohort 1 85 103 78 nCohort 2 26 7 22 Cutoff 1 0.0197 0.0197 0.0197 Sens 1 81% 86% 82% Spec 1 21% 21% 21% Cutoff 2 0.0197 0.0197 0.0197 Sens 2 81% 86% 82% Spec 2 21% 21% 21% Cutoff 3 0 0 0.0162 Sens 3 100%  100%  91% Spec 3  0%  0%  9% Cutoff 4 0.0317 0.0317 0.0700 Sens 4 19% 29% 18% Spec 4 71% 73% 71% Cutoff 5 2.48 1.46 4.64 Sens 5 12% 29%  9% Spec 5 80% 81% 81% Cutoff 6 33.1 25.8 43.5 Sens 6  4% 14%  0% Spec 6 91% 90% 91% OR Quart 2 2.8 2.0 2.9 p Value 0.12 0.58 0.17 95% CI of 0.76 0.17 0.64 OR Quart2 11 23 13 OR Quart 3 2.4 2.1 1.8 p Value 0.20 0.56 0.44 95% CI of 0.63 0.18 0.39 OR Quart3 9.2 24 8.7 OR Quart 4 1.4 2.0 2.9 p Value 0.67 0.58 0.17 95% CI of 0.32 0.17 0.64 OR Quart4 5.7 23 13

While the invention has been described and exemplified in sufficient detail for those skilled in this art to make and use it, various alternatives, modifications, and improvements should be apparent without departing from the spirit and scope of the invention. The examples provided herein are representative of preferred embodiments, are exemplary, and are not intended as limitations on the scope of the invention. Modifications therein and other uses will occur to those skilled in the art. These modifications are encompassed within the spirit of the invention and are defined by the scope of the claims.

It will be readily apparent to a person skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention.

All patents and publications mentioned in the specification are indicative of the levels of those of ordinary skill in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.

The invention illustratively described herein suitably may be practiced in the absence of any element or elements, limitation or limitations which is not specifically disclosed herein. Thus, for example, in each instance herein any of the terms “comprising”, “consisting essentially of” and “consisting of” may be replaced with either of the other two terms. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention that in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.

Other embodiments are set forth within the following claims. 

We claim:
 1. A method for the prophylactic treatment of a subject based on an increased risk of acute kidney injury, comprising: obtaining a urine sample from the subject; performing an assay configured to measure 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex by introducing the urine sample obtained from the subject into an assay instrument which (i) contacts all or a portion of the urine sample with one or more binding reagents which specifically bind for detection 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex and (ii) generates an assay result indicative of binding of 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex to its respective binding reagent; correlating the assay result or a value derived therefrom to the renal status of the subject by using the assay result or value to assign the subject to one of at least two predetermined subpopulations of individuals, wherein a first of the subpopulations has at least a two-fold higher odds ratio of future acute renal injury occurring within 72 hours of the time the urine sample is obtained, the odds ratio calculated relative to a second of the subpopulations; and treating the subject based on the predetermined subpopulation of individuals to which the patient is assigned, wherein the treatment comprises one or more of initiating renal replacement therapy, withdrawing delivery of compounds that are known to be damaging to the kidney, delaying or avoiding procedures that are known to be damaging to the kidney, and modifying diuretic administration if the patient is assigned to the first of the subpopulations.
 2. A method according to claim 1, wherein said assay result comprises a measured concentration of 72 kDa type IV collagenase:Metalloproteinase inhibitor 2 complex.
 3. A method according to claim 1, wherein a plurality of assay results, one of which is the are combined using a function that converts the plurality of assay results into a single composite result.
 4. A method according to claim 1, wherein the subject is not suffering from an acute kidney injury at the time the urine sample is obtained.
 5. A method according to claim 4, wherein the future acute renal injury occurring within 72 hours is a future acute renal injury occurring within 24 hours.
 6. A method according to claim 1, wherein the subject is selected for evaluation of renal status based on the pre-existence in the subject of one or more known risk factors for prerenal, intrinsic renal, or postrenal ARF.
 7. A method according to claim 1, wherein the subject is selected for evaluation of renal status based on an existing diagnosis of one or more of congestive heart failure, preeclampsia, eclampsia, diabetes mellitus, hypertension, coronary artery disease, proteinuria, renal insufficiency, glomerular filtration below the normal range, cirrhosis, serum creatinine above the normal range, sepsis, injury to renal function, reduced renal function, or ARF, or based on undergoing or having undergone major vascular surgery, coronary artery bypass, or other cardiac surgery, or based on exposure to NSAIDs, cyclosporines, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, or streptozotocin.
 8. A method according to claim 4, wherein the future acute renal injury occurring within 72 hours is a future acute renal injury occurring within 48 hours. 